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inkin 
Feeling  -  Doin 


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4- 


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A,  B,  C,  Blind-spot  Figures  (see  page  149,  note). 
D,  Fluctuation  Figure  (see  page  151). 


T  hinking 
Feeling,     Doing 

An  Introduction  to  Mental  Science 


By 
E,  W.  Scripture,  Ph.D.,  M.D. 

Assistant  Neurologist,  Columbia  University 


Second  Edition,  Revised 


Illustrated 


G.  P.  Putnam's  Sons 

New  York  and  London 

Q;be   •RnicF^crbockec    press 
1907 


2 


1901 


Copyright,  1895 

BY 

E.  \V.  SCRIPTURE 
Copyright,  1Q07 

BV 

E.  W.  SCRIPTURE 


Ubc  Itnlcfterbocfter  pteas,  flew  BJorR 


CO 

LU 

a 


PREFACE  TO  THE  SECOKD  EDITION 

THE  first  edition  underwent  many  vicissitudes.  It 
bad  a  phenomenal  sale — over  20,000  copies  the 
publishers  said.  More  than  half  the  book  appeared 
with  a  few  changes  of  phraseology,  but  entirely  un- 
credited,  as  a  small  book  on  psychology  by  a  school 
principal.  A  translation  into  Mandarin  Chinese  was 
prepared  by  Prof.  Headland,  of  Peking  University, 
but  the  buildings  of  the  university  were  burned  during 
the  Boxer  outbreak  in  1900,  and  both  manuscript  and 
plates  were  lost. 

The  first  edition  was  exhausted  and  a  second  was 
called  for  in  1900.  In  spite  of  a  promise  to  furnish 
the  revision  promptly  I  have  been  hindered  from 
doing  it  by  scientific  work  and  other  duties.  I  feel 
that  I  owe  an  earnest  apology  to  persons  who  have 
been  seeking  copies  of  the  book  and  to  the  publishers 
who  have  waited  with  patience  and  courtesy. 

It  is  quite  impossible  to  give  credit  to  all  to  whom  it 
is  due.  The  references  to  the  investigators  who  have 
built  up  the  new  psychology  may  be  found  in  more 
technical  works,  such  as  those  of  Wundt ;  full  litera- 
ture is  given  in  Titchener's  laboratory  manuals  and  in 
Bald  win 's  Dictionary  of  Ph  ilosophy.  Wliere  the  material 
of  this  volume  has  not  been  drawn  from  other  investi- 
gators, it  is  the  work  of  myself  and  my  pupils  in  the 
Yale  Psychological  Laboratory.    Figure  13  is  from  an 

iii 


iv        Preface  to  the  Second  Edition 

investigation  by  McAllister ;  24,  30,  57,  79,  80, 177, 180, 
from  Gilbert ;  31-33  from  Marey ;  42  from  Miyake  ;  45 
from  Bliss ;  50-55  from  Ilensen  ;  59-02  from  Fere ;  78, 
81,  166-171  from  Wundt;  105  from  Kirsclimann  ;  138 
-141,  148-156  from  Martius-Matzdorff ;  157-164  from 
an  art  catalogue;  165  from  Witmer ;  and  176  from 
Wolfe.  The  figures  for  the  optical  illusions  liave  been 
so  frequently  repeated  that  it  seems  impossible  to  as- 
sign credit. 

Vanderbilt  Clinic,  Columbia  University, 
October,  1907. 


PREFACE  TO  THE  FIRST  EDITION 

A  FELLOW  psychologist  said  to  me  one  day,  "Are 
you  not  afraid  that  all  this  accurate  and  fine 
work  in  the  laboratory  will  scare  away  the  public?  " 
.  .  .  We  all  belong  to  the  great  public  except  in 
regard  to  the  particular  handiwork,  trade,  or  science 
that  each  knows  something  about.  And  yet  we  are 
all  interested  in  hearing  about  a  new  science.  There 
is  nothing  too  good  for  the  public — the  finer  the  work, 
the  more  novel  the  invention,  or  the  more  important 
the  discovery,  the  greater  the  duty  of  telling  it  to  the 
public  in  language  that  can  be  understood. 
This  is  the  first  book  on  the  new,  or  experimental, 
psychology  written  in  the  English  language. 

Yale  University,  Jan.,  1895. 


CONTENTS 

CHAPTER  PAGB 

I.  Watching  and  Testing  ;  or  Observation  and 

Experiment 1 

II.  Time  and  Action 13 

III.  Reaction-Time .25 

rv.  Thinking-Time 37 

V.  Rhythmic  Action 52 

VI.  Steadiness 61 

VII.  Power  and  Will 69 

VIII.  Touch 77 

IX.  Hot  and  Cold 87 

X.  Smell  and  Taste 92 

XI.  Hearing 101 

xn.  Colour .        .        .120 

XIII.  Colour  Sensitiveness 130 

XIV.  Seeing  with  One  Eye 145 

XV.  Seeing  ^VITH  Two  Eyes 163 

XVI.  Feelings,  Emotions,  Moods 177 

XVII.  Attention 193 

XVIII.  Memory 203 

XIX.  Suggestion  and  Expectation        ....  217 

XX.  General  Problems 229 

XXI.  Materialism  and  Spiritualism  in  Psychology.  240 

XXII.  The  New  Psychology 247 

Index 257 

vii 


ILLUSTRATIONS 


Blind-spot  Figures  and  Fluctuation  Figure       Frontispiece 

PAGE 


1.  An  Exercise  in  Observation 

2.  An  Exercise  in  Quick  Observation     . 

3.  Apparatus  for  Recording  Time 

4.  A  Specimen  Record     .... 

5.  Electric  Key 

6.  Influence  of  Fatigue  on  Tapping-time 

7.  Influence  of  Mental  Activity  on  Tapping-time 

8.  Rapidity  of  Tapping  as  Dependent  on  Age 

9.  Fatigue  in  Tapping  as  Dependent  on  Age 

10.  Measuring  the  Simultaneity  in  Actions  of  a  Piano 

player 

11.  Result  of  the  Experiment  in  Fig.  10 

12.  Tap  Counter 

13.  Experimental  Writing-Board 

14.  A  Series  of  Reactions 

15.  Chain  Reaction   . 

16.  In  the  Reaction-room 

17.  Reaction-key 

18.  Curve  of  Practice 

19.  Curve  of  Habit   . 

20.  The  Pistol-key     . 

21.  The  Runner's  Key 

22.  Measuring  a  Runner's  Reaction-time 

23.  The  Touch-key    .... 

24.  Reaction-time  Decreases  with  Age 

25.  The  Voice-key     .... 

26.  Measuring  Mental  and  Muscular  Time  in  Fencing 

27.  Apparatus  for  Measuring  Rapidity  of  Thought  and 

Action 

28.  Measuring  how  Rapidly  a  Pugilist  Thinks  and  Acts. 


10 
13 
14 
15 
16 
17 
17 
18 

19 
20 
21 
23 
25 
26 
28 
29 
31 
31 
33 
33 
34 
35 
36 
41 
43 

44 
45 


IX 


Illustrations 


FIGURE 

29. 
30. 
31. 
32. 

33. 
34. 
35. 
36. 
37. 
38. 
39. 
40. 
41. 

42. 
43. 

44. 
45. 
46. 
47. 
48. 
49. 
50. 
51. 
52. 
53. 
54. 
55. 
56. 
57. 
58. 
59. 
60. 

61. 


Measuring  how  Fast  a  Dog  Thinks 

Time  of  Thought  at  Various  Ages  in  School  Children 

The  Pneumatic  Shoe 

Walking    witli  Pneumatic    Shoes    and  Recording 

Drum 

Graphic  Records  of  Walking  and  Running 

The  Electric  Shoe 

Regular  Retarded  Rhythm 

Irregular  Retarded  Rhythm 

Regular  Accelerated  Rhythm     . 

Irregular  Accelerated  Rhythm  . 

Regular  Accurate  Rhythm 

The  Electric  Baton    .  .... 

Taking    an  Orchestra    Leader's    Record  with  the 

Electric  Baton 
Record  of  Arhythmic  Action 
Arrangement    of    Capsules  for   Steadiness  under 

Guidance  of  the  Eye      .... 
Taking  a  Record  of  Steadiness  . 

A  Record  of  Steadiness 

Recording  a  Sportsman's  Unsteadiness 

Steadiness-gauge 

Measuring  Steadiness  and  Attention 

Result  of  Educating  Attention  to  the  Arm 

Testing  Steadiness  in  Singing.     The  Unison 

Singing  the  Octave 

Singing  the  Duodecime 

Singing  the  Fifth 

Singing  the  Fourth 

Singing  the  Third 

Spring  Dynamometer 

Weight- judgments  in  School  Children 

Dynamograph      ..... 

Grip  of  the  Hand  by  a  Hysterical  Person 

Successive  Squeezes  during  Ringing  of  a  Gong  and 

during  Silence 
Strongest  Contractions  while  Looking  at  Different 
Colours        .... 


PAGE 

46 
48 
52 

53 
53 
53 
54 
55 
55 
55 
55 
56 

57 
59 

61 
62 

63 
63 
64 
65 
66 
67 
68 
68 
68 
68 
68 
69 
71 
74 
75 

75 


Illustrations 


XI 


FIGURE 

62.  . 
63. 
64. 
65. 

66. 
67. 

68.  • 

69. 

70. 

71. 

72. 

73. 

74. 

75. 

76. 

77. 

78. 

79. 
80. 
81. 

82. 
83. 
84. 
85. 
86. 
87. 


89. 
90. 
91. 
92, 
93. 
94. 
95. 
96. 


Influence  of  Musk 76 

Touch-Weights  for  Finding  the  Threshold        .         .  77 

Finding  the  Threshold  for  the  Palm  of  the  Hand     .  78 

Finding  the  Least  Noticeable  Change  in  Pressure.     .  79 

Simple  ^sthesiometer 83 

The  Complete  ^sthesiometer 84 

Aristotle's  Illusion 85 

A  Cold-spot  Map 88 

A  Hot-spot  Map           ....                 .         .  88 

Finding  the  Hot  and  Cold  Spots         ....  89 

Boiling  a  Frog  without  His  Knowing  It  .         .         .91 

Olfactometer 93 

Alternation  of  Odours 95 

Giant  Fork  for  Finding  the  Lowest  Audible  Tone    .  102 
Whistle  for  Determining  the  Highest  Audible  Tone  103 
The  Highest  Audible  Tone  as  Dependent  on  Inten- 
sity     106 

Forks  of  Adjustable   Pitch   for  Finding  the  Least 

Noticeable  Difference 107 

The  Tone-tester 110 

Error  in  Hearing  Decreases  with  Age        .         .         .111 

Apparatus  for  Finding  the  Middle  Tone    .         .         .  113 

Finding  the  Threshold  of  Intensity  for  Hearing       .  115 

Method  of  Indicating  Intensity  in  Notes  .         .         .  117 
Series  of  Notes  According  to  Duration     .         .         .118 

System  of  Greys,  or  Neutral  Colours          .         .         .  120 

System  of  the  Brightest  Colours  and  the  Tints        .  121 
Systems     of  Greys,   Shades,    Greyish    Tints    and 

Greyish  Shades 121 

System  of  all  the  Colours 122 

The  Colour-top 123 

The  Colour-wheel 123 

Putting  Two  Disks  Together 124 

Two  Disks  with  Scale 124 

Spectrum  from  a  Grating 125 

The  Colour  Triangle 127 

Mixing  Yellow  and  Blue 128 

Getting  the  Grey  Equation        .....  131 


Xll 


Illustrations 


FIGURE 

97.  Trichromats         .... 

98.  Dichromats  of  the  First  Class     . 

99.  Dichromats  of  the  Second  Class 

100.  Monochromats     .... 

101.  Colour-sense  tester 

102.  Disk  to  Illustrate  Effect  of  Contrast 

103.  Figure  for  After  Images 

104.  Perimeter,  for  Measuring  the  Field  of  Vision 

105.  Perimeter  Chart  for  Colours 

106.  Diagram  for  Finding  the  Blind-Spot 

107.  Putting  a  White  Circle  on  the  Blind-Spot 

108.  The  Circle  is  Replaced  by  the  Colours 

109.  What  Will  Happen  Now    ? 

110.  The  Result  .... 

111.  A  Puzzler  for  the  Blind-Spot 

112.  What  the  Eye  Considers  to  be  Equal  Distances 

113.  A  Misplaced  Line 

114.  Illusion  of  the  Interrupted  Distance 

115.  The  Distorted  Squares 

116.  The  Enlarged  Angle   . 

117.  Illusion  of  Filled  Space 

118.  Displacement  by  Inclined  Lines 

119.  Breaking  Parallel  Lines 

120.  Tipping  Parallel  Lines 

121.  Bending  Straight  Lines 

122.  A  Misplaced  Line 

123.  A  Misplaced  Line 

124.  A  Tipped  Line     . 

125.  Changing  the  Length  of  a 

lines 

126.  The  Coin  Illusion 

127.  An  Overhanging  Cornice,  or  a  Stairway  ? 

128.  The  Changing  Rings  o 

129.  Shape  of  the  Sky 

130.  The  Moon  Illusion 

131.  Book  Seen  with  the  Right  Eye 

132.  Book  Seen  with  the  Left  Eye 

133.  The  Real  Book    . 


Line 


by  Different  Cross 


132 
133 
134 
135 
139 
142 
143 
146 
147 
148 
149 
149 
150 
150 
151 
152 
152 
153 
153 
153 
154 
154 
155 
155 
156 
156 
156 
156 

157 
158 
158 
158 
160 
160 
16S 
168 
164 


Illustrations  ^^ 

FIGURE  PAGE 

134.  Book  as  Actually  Seen 164 

135.  Put  the  Bird  in  the  Cage  by  Binocular  Vision  .         .165 

136.  The  Prism  Stereoscope 166 

137.  The  Book  Stereoscope 166 

138.  Two  Like  Pictures 167 

139.  Unlike  Pictures  to  be  Combined        .         .         .        .167 
140;  Prometheus 168 

141.  TheH 168 

142.  Crossed  Disparity 169 

143.  Uncrossed  Disparity .  169 

144.  What  we  would  Expect  when  Looking  at  the  Farther 

End 170 

145.  What  we  would  Expect  when  Looking  at  the  Nearer 

End ,         .  170 

146.  What  we  would  Expect  when  Looking  at  the  Middle  170 

147.  What  we  Actually  See        .        .        .         ,        .        .170 

148.  The  Pyramidal  Box 170 

149.  The  Funnels 171 

150.  The  Crystals 171 

15i.  The  Multiple  Star 173 

153.  The  Complicated  Pyramids 173 

153.  The  Thread  Figure 173 

154.  Binocular  Strife 174 

155.  Binocular  Lustre 175 

156.  A  Binocular  Illustration  to  Milton's  Paradise  Lost .  176 

157.  Single  Symmetry,  Horizontal 183 

158.  Single  Symmetry,  Vertical 183 

159.  Double  Symmetry 183 

160.  Threefold  Symmetry 183 

161.  Fourfold  Symmetry 188 

163.  Eightfold  Symmetry 183 

163.  Perfect,  but  Simple  Symmetry  in  All  Directions    .  183 

164.  Combinations  of  Symmetry 184 

165.  Law  of  Pleasing  Relations  of  the  Dimensions  of  a 

Rectangle 184 

166.  Effect  of  Attention  on  Respiration    ....  186 

167.  Effect  of  Attention,  Plethysmograph  Record  .         .  187 

168.  Respiration  and  Arm  Curve  during  Tension  and  Re- 

laxation     187 


XIV 


Illustrations 


169.  Effect  of  a  Stimulating  Thought 

170.  Effect  of  a  Depressing  Thought 

171.  Effect  of  Dislike .... 

172.  Focus  and  Field  of  Attention     . 

173.  A  Leaf  from  Daisy's  Copy-book 

174.  Symmetrical  and  Direct  Cross-memory 

175.  Measurements  on   Symmetrical  and  Direct  Cross- 

memory  ...         ... 

176.  Law  of  Forgetting  Tones  . 

177.  Dependence  of  Time-memory  on  Age 

178.  Producing  a  Hallucination  of  Warmth 

179.  Blocks  for  Measuring  the  Effect  of  a  Suggestion  of 

Size 

180.  Dependence  of  the  Effect  of  Suggestion  on  Ag( 

Sex 

181.  Actual  Positions  of  the  Star  at  the  Pendulum- 
183.  Supposed  Positions  with  Visual  Attention 

183.  Supposed  Positions  with  Auditory  Attention 

184.  Johann  Friederich  Herbart 

185.  Gustav  Theodor  Fechner    .... 

186.  Hermann  von  Helmholtz    .... 

187.  Wilhelm  Wundt 


eand 


beats 


187 
188 
188 
194 
205 
206 

207 
208 
215 
218 

219 

221 
227 
227 
228 
249 
251 
252 
254 


THINKING,    FEELING,    DOING 


THINKING,  FEELING,  DOING 


CHAPTER  I 

WATCHING     AND     TESTING;     OR     OBSERVATION     AND 

EXPERIMENT 

THE  fundamental  method  of  acquiring  knowledge 
is  observation,  or  watching.  We  watch  our 
thoughts  and  feelings  to  know  what  goes  on  in  our 
own  minds ;  we  watch  the  actions  of  others  to  draw 
conclusions  concernino:  their  thousfhts  and  feelings. 

A  great  difficulty  lies  in  the  fact  that  the  act  of 
observing  may  change  the  person  or  thing  to  be  ob- 
served. Every  public  man  wears  a  mask,  because  he 
is  watched.  If  we  wish  to  know  just  Nvhat  kind  of  a 
man  he  is,  we  must  watch  him  in  unsuspected  mo- 
ments. A  great  deal  of  ridicule  has  been  cast  on  the 
enthusiasts  wlio  prv  into  the  most  intimate  details  of 
a  statesman's  or  poet's  private  life.  In  one  respect 
these  men  are  quite  in  the  right.  They  say  to  them- 
selves, "  The  public  is  interested  in  knowing  just  what 
the  man  really  is  when  he  has  his  mask  off." 

If  there  is  anything  wrong  about  this,  it  is  not 
the  method  ;  just  this  method  is  to  be  used  in  acquir- 
ing all  knowledge.  In  fact,  I  shall  want  you  to  watch 
the  processes      thinking,  feeling,  and  doing,  in  exactly 


2  Thinking,  Feeling,  Doing 

the  same  fashion.  Lie  in  wait,  concealed ;  catch  jour 
"  process  "  going  on  in  a  perfectly  natural  way.  More- 
over, strange  as  it  may  seem,  this  is  the  only  way,  the 
fundamental  rule  being  that  the  act  of  watching  must 
not  change  the  person  or  thing  watched. 

It  is  not  sufficient  to  know  this  rule;  we  must  be 
constantly  on  guard  against  several  very  dangerous 
sources  of  error.  The  first  is  the  error  of  prejudice. 
Grandmother  M.  has  used  Dr.  Swindle's  liver  pills  all 
her  life  long.  She  always  believed  they  would  do  her 
good ;  she  remembers  the  dozen  times  she  happened 
to  feel  better  after  taking  them  and  forgets  the  hundreds 
of  times  she  did  not.  Therefore  she  has  facts — in- 
contestable facts — to  prove  the  goodness  of  the  pills. 
Possibly  her  picture  appears  in  the  newspaper  with 
an  enthusiastic  testimonial.  It  is  useless  to  attempt  to 
convince  her  that  her  method  of  observation  has  been 
vitiated  by  the  error  of  prejudice. 

Of  course,  this  error  is  very  plain  in  other  people, 
but  most  of  us  believe  that  we  always  judge  fairly. 
But  to  think  scientifically  we  must  realise  that  each 
one  of  us  is  so  biased  by  prejudice  that  in  many  ways 
we  cannot  possiblj^  observe  correctly. 

To  show  that  everj^body  is  prejudiced,  let  me  ask 
3^ou  such  questions  as :  Have  you  not  some  pet  fad 
on  which  you  are  sure  you  are  right  and  all  the  rest  of 
the  town  are  wrong  ?  Are  you  not  quite  sure  that  there 
is  only  one  side  to  the  tariff  question  ?  Are  you  not 
astounded  at  the  fact  that  some  people  find  a  good 
side  to  a  man  you  know — yes,  know — to  be  utterly 
bad  ?  Don't  be  ashamed  to  confess.  The  great  scientist 
Faraday  did.     "It  is  my  firm  opinion  that  no  man 


Watching  and  Testing  3 

can  examine  himself  in  the  most  common  things 
having  any  reference  to  him  personally  or  to  any 
person,  thought,  or  matter  related  to  him  without  soon 
being  made  aware  of  the  temptation  to  disbelieve  con- 
trary facts  and  the  difficulty  of  opposing  it.  I  could 
give  you  many  illustrations  personal  to  myself  about 
atmospheric  magnetism,  lines  of  force,  attraction,  re- 
pulsion, etc." 

Seven  alienists  of  2:ood  standinsr  swore  that  accordingr 
to  the  facts  before  them  a  certain  murderer  was  sane ; 
they  were  employed  by  the  prosecution  at  $100 
a  day.  The  defence  employed  seven  equally  good 
alienists  at  $150  a  day  ;  these  swore  that  according  to 
the  same  facts  the  man  was  insane.  Everyone  of  these 
men  was  honest  in  his  opinion — at  least  as  far  as  his 
consciousness  went;  there  was  at  work  a  cause  which 
unconsciously  led  him  to  give  his  opinion  in  a  certain 
way  :  he  was  paid  to  do  so.  How  shall  such  errors  of 
prejudice  be  avoided  ?  In  Germany  the  court  sends 
for  any  expert  it  pleases  ;  his  pay  is  $2  a  day  with  no 
compensation  for  the  damage  done  to  his  profession  or 
business ;  if  he  is  not  willing  to  serve,  the  policeman 
brings  him  to  court  by  force.  He  has  no  motive  for 
rnakinor  his  observation  favour  either  side  and  he  is 
punished  for  any  laxity  or  misrepresentation.  Among 
scientific  men  preconceived  opinions,  the  fear  of  taking 
back  anything  that  has  been  published  and  the  desire 
to  achieve  novel  results  produce  the  "will  to  ob- 
serve "  that  makes  us  see  so  man}^  things  that  do  not 
exist.  How  shall  we  combat  the  error  ?  Several  ways 
are  possible.  TVe  may  use  moral  suasion.  We  may 
partly  remove  the  motives  by  agreeing  to  recognise 


4  Thinking,  Feeling,  Doing 

that  the  withdrawal  of  an  erroneous  statement  is  a 
most  honourable  thing.  We  may  also  learn  to  recognise 
that  the  reverence  for  the  "  old  "  is  the  most  misleading 
of  all  guides.  Not  much  is  to  be  hoped  from  such 
methods ;  the  best  method  is  to  force  the  investigator 
to  arrange  experiments  and  recording  instruments  so 
that  the  facts  can  speak  for  themselves.  We  can  thus 
"police"  a  man's  statements  by  obliging  him  to  fur- 
nish experimental  proof  for  them.  This  is  what  the 
new  psychology  tries  to  accomplish. 

Another  very  dangerous  error  is  that  of  unconscious 
additions. 

Play  the  game  of  twent}^  questions.  The  company 
choose  some  object  and  some  one  who  does  not  know 
what  has  been  chosen  has  to  guess  it  from  the  answers 
"Yes"  or  "No"  to  his  questions.  Stop  him  when  be 
is  half  through  and  ask  him  to  tell  ^-ou  what  he  con- 
cluded from  the  different  answers.  You  will  find  that 
he  adds  far  more  than  is  justified  bv  the  answer  to  each 
question.  For  example,  something  chosen  is  neither 
animal  nor  mineral;  it  is,  therefore,  so  the  questioner 
thinks,  "  a  "  vegetable.  But  suppose  j'ou  had  chosen 
"  buckwheat  cakes  "  ? 

This  error  is  one  of  the  most  troublesome  ones  in 
reading  printer's  proof;  letters  and  words  that  have 
been  omitted  by  the  compositor  are  unconsciously  sup- 
plied by  the  reader.  An  author,  on  account  of  his 
interest,  is  more  liable  to  this  error  than  any  one  else  ; 
he  is  generally  a  very  unreliable  proof-reader. 

A  familiar  case  of  this  error  is  found  in  the  story  of 
the  ten  white  crows — which  I  will  leave  the  reader  to 
hunt  up  in  his  old  school  books. 


Watching  and  Testing  5 

This  source  of  error,  as  Wunclt  has  pointed  out, 
renders  almost  absolutely  worthless  an  enormous 
amount  of  painstaking  work  in  animal  psycliology. 
The  facts  are  observed  and  collected  with  untiring 
diligence,  but  the  critical  study  of  the  results  is  gen- 
erall}^  entirely  lacking. 

Take,  for  example,  a  case  reported  by  Romanes  in 
his  volume  on  anim^al  intelligence. 

An  Eno'lisli  clercryman  writes  concernino;  the  "  fu- 
nereal  habits  "  of  ants :  "I  have  noticed  in  one  of  my 
formicaria  a  subterreanean  cemetery,  where  I  have 
seen  some  ants  burying  their  dead  by  placing  earth 
above  them.  One  ant  was  evidently  much  affected, 
and  tried  to  exhume  the  bodies  ;  but  the  united  exer- 
tions of  the  yellow  sextons  were  more  than  sufficient 
to  neutralise  the  effort  of  the  disconsolate  mourner." 

Wundt  asks,  How  much  is  fact,  and  how  much 
imagination  ?  It  is  a  fact  that  the  ants  carry  out  of  the 
nest,  deposit  near  by,  and  cover  up  dead  bodies,  just 
as  they  do  anj'thing  else  that  is  in  their  way.  They 
can  then  pass  to  and  fro  over  them  without  hin- 
drance. In  the  observed  case  they  were  evidently  inter- 
rupted in  this  occupation  by  another  ant,  and  resisted 
its  interference.  The  cemetery,  the  sextons,  the  feelings 
of  the  disconsolate  mourner,  which  impelled  her  to  ex- 
hume the  body  of  the  departed — all  this  is  the  fiction 
of  the  sympathetic  imagination  of  the  observer. 

Another  friend  of  ants  gives  this  account:  "  At  one 
formicary  half  a  dozen  or  more  3^oung  queens  were 
out  at  the  same  time.  They  would  climb  up  a  large 
pebble  near  the  gate,  face  the  wind,  and  assume  a 
rampant  posture.    Several  having  ascended  the  stone  at 


6  Thinking,  Feeling,  Doing 

one  time,  there  ensued  a  little  playful  passage-at-arms 
as  to  position.  Tiiey  nipped  each  other  gently 
with  the  mandibles,  and  chased  one  another  from 
favourite  spots.  They,  however,  never  nipped  the 
workers.  These  latter  evidently  kept  a  watch  upon 
the  sportive  princesses,  occasionally  saluted  them  with 
their  antennae  in  the  usual  way,  or  touched  them 
at  the  abdomen,  but  apparently  allowed  them  full 
liberty  of  action." 

The  correctness  of  this  observation,  says  Wundt, 
need  not  be  questioned.  Why  should  not  a  number 
of  voung  queens  have  been  crowded  together  upon  a 
pebble,  and  some  workers  have  been  with  them,  and 
occasionally  touched  them  with  their  antennae,  as  ants 
do  everywhere  ?  But  that  they  "  sported  "  and  played, 
that  the  others  "  kept  watch  upon  them  "  like  chaper- 
ones,  and  now  and  again  did  homage  to  them  by 
"  saluting  " — all  this  is  due  to  the  imagination  of  the 
observer.  He  would  hardly  have  told  the  story  in  this 
way  had  not  the  suggestive  name  "  queen ''  been  in- 
troduced for  the  mature  female  insects.  If  the  adults 
are  "  queens "  the  young  ones  must,  of  course,  be 
''  princesses  "  to  the  other  ants  as  well  as  in  the  imag- 
ination of  the  observer.  And  since  no  princess  ever 
went  out  without  an  attendant  or  a  chaperone,  the  rest 
of  the  tale  follows  as  a  matter  of  course.  If,  instead 
of  the  name  "  queen,"  the  mature  female  ant  had 
been  called  by  the  still  better  term  "  mother,"  we 
would  have  had  an  entirely  different  story  from 
the  same  facts.  I  leave  it  to  my  readers  to  tell 
it. 

It  is  this  activity  of  the  imagination  that  turns  men 


Watching  and  Testing  ^ 

of  perfectly  honest  intentions  into  ''nature  fakers"  in 
their  stories  of  animals. 

How  easy  it  is  to  misinterpret  an  observation  if  the 
very  greatest  care  is  not  taken  in  recording  it,  and  if  it 
is  impossible  to  vary  the  circumstances  by  experiment 
and  thus  to  obtain  accurate  knowledge  of  the  details, 
is  well  shown  by  the  following  facts. 

Pierre  Huber,  one  of  the  most  reliable  students  of 
the  habits  of  ants,  stated  that  he  had  assured  himself 
that  an  ant,  if  taken  from  the  nest  and  returned  after 
an  interval  of  four  months,  was  recognised  by  its 
former  companions ;  for  they  received  it  in  a  friendly 
manner,  while  members  of  a  different  nest,  even 
though  they  belonged  to  the  same  species,  were  driven 
away.  The  correctness  of  the  observation  cannot  be 
doubted ;  it  has  also  been  confirmed  by  Lubbock. 
Lubbock,  however,  made  the  matter  a  subject  of  ex- 
periment. He  took  ant  larvae  from  the  nest  and  did 
not  put  them  back  till  they  were  fully  developed. 
They,  too,  were  received  in  a  friendly  manner,  al- 
though there  could  be  no  question  of  resemblance  be- 
tween the  larva  and  the  grown  ant.  There  must, 
therefore,  be  some  characteristic  peculiar  to  all  mem- 
bers of  a  particular  nest,  possibly  a  specific  odour, 
which  determines  the  "  friendliness  "  of  the  ants. 

I  shall  warn  you  against  only  one  error  more,  that  of 
untrustworthiness  of  the  senses,  as  it  is  called.  Sir 
Walter  Raleigh  was  one  day  sitting  at  a  window  when 
he  observed  a  man  come  into  the  courtyard  and  go  up 
to  another  standing  by  the  door.  After  a  few  words 
the  latter  drew  his  sword,  they  fell  to  fighting,  and  the 
first  comer  was  finally  wounded  and  carried  out.     A 


8  Thinking,  Feeling,  Doing 

person  who  had  been  standing  close  beside  the  door 
afterwards  flatly  contradicted  the  observation  of  Sir 
Walter,  saying  that  the  man  at  the  door  had  not  been 
the  first  to  draw  his  sword  and  that  it  was  not  the  first 
comer  who  was  wounded  and  carried  out.  Sir  Walter's 
senses  had  deceived  him.  Note  the  flat  contradictions 
of  eye-witnesses  in  the  next  trial  you  read  about. 
Let  us  now  take  a  few  lessons  in  observing. 

1.  Below  on  this  page  you  will  find  a  figure. 
Write  what  you  see.  I  am  not  going  to  tell  you 
another  thing  about  it ;  not  even  what  the  exercise  is 
for.  Show  the  figure  to  other  people  with  the  same 
directions.  Compare  your  result  with  theirs.  Just  as 
you  progress  in  understanding  what  the  exercise  is 
for,  just  so  far  will  you  have  profited  by  it. 

2.  On  the  second  page  from  this  you  will  find  a 
number  of  letters  printed  in  a  square.  Turn  over  the 
page  for  just  an  instant  and  then  close  the  book. 
What  letters  can  you  remember?  You  can  readily 
prepare  a  set  of  cards  witli  various  combinations  of 
letters  and  can  train  your  friends  in  observing.  Or 
you  can  use  cut  letters,  such  as  go  under  the  name 
of  letter-tablets.     Make  irregular  combinations  on  the 


* 


o 

Fig.  1.— An  Exercise  in  Observation. 

table  behind  a  screen  of  some  kind,  e.  ^.,  a  book  ; 
snatch  the  book  away  for  an  instant,  and  have  the 
onlookers  write  down  the  ones  they  saw.     Then  form 


Watching  and  Testing  9 

words  instead  of  letters.  You  will  notice  that  people 
can  catch  almost  as  many  words  as  they  can  catch  dis- 
connected letters.  Or  you  can  write  on  a  slate  and 
turn  it  over  for  an  instant     Or  you  can  use  dominoes. 

3.  Place  a  number  of  objects  on  a  table  in  the  next 
room.  Let  each  person  go  in  and  walk  once  around 
the  table  during  the  time  you  count  twenty.  Coming 
out  he  is  to  write  down  a  list  of  what  he  saw. 

At  first  you  can  catch  almost  nothing  in  the  last 
two  exercises.  It  is  very  important  to  continue  the 
practice  ;  you  cannot  go  too  far.  You  will  be  encour- 
aged by  knowing  that  the  magician  Robert-Houdin 
began  in  the  same  way.  He  and  his  son  would  pass 
rapidly  by  a  shop-window  and  cast  an  attentive  glance 
at  it  A  few  steps  farther  they  noted  down  on  paper 
the  objects  they  had  seen.  The  son  could  soon  write 
down  forty  objects.  This  training  was  kept  up  till  an 
astounding  ability  was  acquired.  On  the  occasion  of 
one  performance  the  son  gave  the  titles  of  more  than  a 
dozen  books  in  another  room  with  the  order  of 
arrangement  on  their  shelves.  He  had  seen  them  in  a 
single  glance  as  he  passed  rapidly  through  the  library. 

There  are  many  women  who  have  unintentionally 
educated  themselves  to  a  high  degree  of  ability  in 
quick  observation.  It  can  be  safely  asserted  of  many  a 
one  of  them  that,  seeing  another  woman  pass  by  in 
a  carriage  at  full  speed,  she  will  have  had  time  to  an- 
alyse her  toilet  from  her  bonnet  to  her  shoes,  and  be 
able  to  describe  not  only  the  fashion  and  quality  of  the 
stuffs,  but  also  say  if  the  lace  be  real  or  only  machine 
made.  It  is  said  that,  when  passing  on  the  street, 
eight  women  out  of  ten  will  turn  around  to  see  what 


lo  Thinking,  Feeling,  Doing 

the  other  one  wears.  I  have  often  wondered  at  the 
two  who  did  not  turn  around — but  the  reason  is  clear  : 
they  did  not  need  to. 

Innumerable  exercises  in  quick  and  accurate  obser- 
vation can  be  used  in  direct  assistance  to  the  resfular 
work  of  the  schoolroom.  The  spelling  of  words  can 
be  learned  by  quick  glances ;  the  outlines  and  parts  of 
a  country  can  be  taught  in  greater  and  greater  detail 
by  successive  quick  exercises;  a  problem  in  mental 
arithmetic  is  to  be  grasped  with  only  a  momentary 
presentation  of  it ;  an  object  is  to  be  drawn  after  an 
instantaneous  glimpse ;  etc.,  etc.  Indeed,  there  is  not 
a  single  school  exercise  that  cannot  be  so  taught  as  to 
train  this  ability.  In  fact,  the  children  are  naturally 
quicker  than  we  suppose  them  to  be  ;  it  is  often  the 
case  that  lessons  of  interest  to  the  child  are  presented 
in  such  a  way  as  to  actually  teach  him  to  be  slow 
instead  of  quick. 

M  B  X         O 

Q  R  A  G 

F  C  W  P 

T  E  D  L 

Fig.  2,— An  Exercise  in  Quick  Observation. 

In  ordinary  observation  we  wait  for  things  to  happen 
in  one  way  or  another ;  possibly   they  never  happen 


Watching  and  Testing  1 1 

in  just  the  circumstances  most  favourable  for  studying 
theni.  In  an  experiment  we  arrange  the  circumstances 
so  that  the  thing  will  happen  as  we  wish.  How  good 
is  the  memory  of  a  certain  child?  We  might  wait  a 
long  time  before  he  happened  to  periorm  some  mem- 
ory exercise  that  would  exactly  answer  the  question. 
Instead  of  this  we  experiment  on  him  by  giving  him 
lines  of  figures,  sets  of  sj-llables,  words,  etc.,  till  we 
know  in  just  what  condition  his  memory  is. 

Yary  only  one  circumstance  at  a  time.  If  you  wish 
to  find  how  strong  a  child's  memory  is  at  difi'erent 
times  of  the  day,  you  should  not  make  the  morning 
test  with  words  and  the  next  with  figures.  There 
might  be  a  difference  due  to  the  change  from  words  to 
figures,  and  you  w^ould  suppose  this  difference  to  be 
due  to  the  time  of  day. 

Experiments  can  be  conveniently  divided  into  three 
grades.  1.  Tests.  The  test  is  the  simj^lest  form  and  is 
an  answer  to  the  question  :  Is  something  so  or  not  so  ? 
Tte  usual  test  on  hypnotised  persons  is  pricking  them 
with  a  pin  to  see  whether  they  feel  or  do  not.  By  flashing 
a  lightwe  determine  whether  a  person  is  absolutely  blind 
or  not.  2.  Qualitative  experiments.  By  these  we  aim  to 
answer  the  question:  What?  In  experiments  on  the 
emotions  we  ask  what  bodily  processes  change  with 
them.  To  determine  what  colour  a  person  can  see,  we 
make  experiments  for  colour-blindness.  8.  Quantitative 
experiments.  How  much  ?  is  the  question  w'e  ask  in  this 
case.  How  small  a  difference  can  you  detect?  How 
many  syllables  can  you  remember  ?  How  quickly  can 
you  think. 

The  objection  is  sometimes  made  that  experiments 


12  Thinking,    Feeling',  Doing 

in  thinking,  feeling,  etc.,  are  physical  and  not  mental. 
This  confuses  the  means  with  the  thing,  the  tools  with 
the  work  done.  The  apparatus  is  physical,  but  your 
accuracy  of  judgment,  your  suggestibility,  your  power 
of  will,  are  mental. 


CHAPTER  II 


TIME    AND   ACTION 

FOR  the  purpose  of  measuring  small  intervals  of 
time  one  of  the  most  convenient  methods  is  the 
graphic  method.  Being  one  of  the  most  beautiful  and 
accurate  methods  of  experiment,  it  is  extensively 
employed  in  physics,  astronomy,  physiology,  and 
psychology. 

The  first  thing  to  be  done  is  to  set  up  a  tuning-fork 
— not  a  little  one,  such  as  musicians  carry  in  the 
pocket,  but  one  a  foot  long,  vibrating  one  hundred 
times  a  second.  By  means  of  a  battery  and  a  magnet 
this  fork  is  kept  going  of  itself  as  long  as  we  please. 
The  prongs  of  the 
fork  move  up  and 
down  one  hun- 
dred times  a  sec- 
ond. Every  time 
the  lower  prong 
moves  downward,  a 
point  on  the  end 
dips  into  a  cup  of 
mercury,  whereby 
an  electric  circuit  is 

closed.      This    elec-         ^^'^'  S— -'^PP^^'^tus  for  Recording  Time. 

trie  circuit  passes  through  a  little  instrument  called  a 

13 


14  Thinking,  Feeling,  Doing 

time-marker,  which  makes  a  light  pointer  move  back  and 
forth  also  one  hundred  times  a  second.  The  point  of 
the  time-marker  rests  on  a  surface  of  smoked-  paper 
around  a  metal  drum.  The  smoked  paper  is  prepared 
by  stretciiing  ordinary  glazed  paper  around  the  drum 
and  holding  a  smoky  gas  or  benzine  flame  under  it.  A 
soft  black  surface  is  thus  obtained,  in  which  the  point 
of  the  marker  draws  a  wavy  line  as  the  drum  is 
turned  (Fig.  4). 


Fig.  4.— a  Specimen  Record. 

Now,  if  the  point  of  the  marker  moves  back  and 
forth  just  one  hundred  times  a  second,  each  complete 
wave  must  mean  0.01^  of  time.  Consequently  if  a  dot 
is  placed  on  the  line  whenever  I  move  my  finger,  as  is 
illustrated  in  Fig.  4,  I  can  tell  just  how  much  time 
elapsed  between  any  two  movements  by  counting  the 
waves  and  the  fraction  of  a  wave.  Thus  the  two  dots 
are  distant  by  seven  whole  waves  and  five-tenths  of  a 
wave  extra;  the  time  is,  therefore,  0.075^  The  wavy 
line  is  called  the  "  time-line." 

In  making  careful  records  in  the  laboratory  it  is 
needful  to  count  in  thousandths  of  a  second,  but  there 
is  so  much  uncertainty  about  the  last  figure  that  in  the 
final  statement  of  results  is  not  only  unnecessary  to 
state  the  thousandths,  but  it  is  also  misleading  on 
account  of  the  false  degree  of  accuracy  implied.  We 
will  therefore  use  hundredths  of  a  second  to  count  by. 


Time  and  Action  15 

In  order  to  save  the  multitude  of  0"s  and  decimal 
points  let  us  introduce  the  sign  2  to  indicate  hundredths 
of  a  second.  We  will  call  the  sis^n  "sis^ma."  Thus 
instead  of  0.08^  we  write  82. 

To  put  dots  on  the  time-line  when  a  finger  is 
moved,  it  is  placed  on  the  button  of  a  special  tele- 
graph key,  so  arranged  tiiat  the  slightest  movement  of 
the  finger  breaks  an  electric  circuit.  Fig.  5  shows  the 
finger  ready  to  make  a  record  when  it  moves  down- 
ward ;  the  electric  circuit  passes  through  the  rear  con- 
tact of  the  key.  This  electric  circuit  runs  through  a 
large  coil  of  wire  which 
makes  a  spark  when- 
ever the  circuit  is 
broken.  Two  wires 
run    from    this    spark-  Fig.  s.-Eiectric  Key. 

coil,  one  to  the  drum  and  the  other  to  a  metal  point 
resting  on  the  smoked  paper.  Whenever  a  spark  is 
made,  it  jumps  through  the  paper  scattering  the  smoke 
and  making  a  white  dot.  In  Fig.  3  the  metallic  point 
is  the  time-marker  itself.  Every  time  we  move  the 
finger  a  dot  is  made  on  the  time-line.  Fig.  4  shows 
the  time  between  two  downward  movements  of  the 
finger.  To  preserve  the  record,  i.  e.,  to  keep  the 
smoke  from  rubbing  off,  the  paper  is  cut  from  the 
drum,  run  through  a  varnish,  and  dried. 

Such  movements  of  the  finger  are  called  "  taps. " 
The  study  of  tapping  enables  us  to  draw  deductions 
concerning  the  will  and  how  it  varies.  For  each  tap 
there  are  two  acts  of  will,  one  to  move  the  fins-er  down 
and  the  other  to  lift  it.  There  is  no  resemblance  or 
relation    between   tapping  and  what   are    known    as 


1 6  Thinking,  Feeling,  Doing 

"  tremors  "  ;  we  can  will  to  tap,  but  we  cannot  will  to 
tremor  ;  the  one  is  voluntary  action,  the  other  involun- 
tary. "Trembling"  is  a  term  applied  sometimes  to 
voluntary  movements  of  the  same  nature  as  tapping, 
sometimes  to  tremors. 

In  one  form  of  experiment  the  person  is  told  to  tap  as 
rapidly  as  he  can.  Series  of  sparks  fly  off  the  end  of 
the  point  of  the  time-marker  in  Fig.  3.  On  counting  up 
the  records  we  obtain  the  number  of  hundredths  of  a 
second  for  each  tap.  A  good  average  rate  is  15-2  per 
tap,  or  nearly  seven  taps  to  the  second.  Faster  records 
have  been  made,  8^  having  been  recorded  for  tapping 
with  the  middle  finger. 

The  rapidity  of  tapping  decreases  with  fatigue.  Fig. 
6  represents  tlie  results  of  a  continuous  series  of  taps, 
the  lower  the  line  the  faster  the  tap  ;  the  straight,  hori- 
zontal line  corresponds  to  a  tap-time  of  lb2  and  the 
short  checks  on  this  line  mark  off  the  seconds.  At 
first  the  tapping  is  rather  irregular,  but  it  is  on  the 
whole  very  rapid,  one  tap-time  being  only  11^.    The 

Fig.  6.— Influence  of  Fatigue  on  Tapping-time. 

tapping  soon  becomes  steadier  and  remains  rapid  for 
about  seventeen  seconds.  After  that  it  is  somewhat 
slower  and  more  irregular,  owing  probably  to  fatigue. 
The  mental  condition  has  a  most  powerful  influence 
on  the  rapidity  of  tapping.  Excitement  makes  the 
tapping  more  rapid.  Tlie  influence  of  distraction  of 
attention  is  shown  in  Fiof.  7.  This  fisfure  has  the  same 
meaning  as  Fig.  6.     Adding  214  and  23  produced  a 


Time  and  Action 


17 


marked  slowness  in  tapping  ;  so  did  the  mental  labour 
of  multiplying  1-i  by  5.  It  requires  some  effort  for  an 
ordinary  man  to  perform  these  calculations,  and  the 
mental  worli  of  association  seemed  to  leave  less  energy 
for  the  work  of  will.  The  figure  seems  to  show  that  mo- 
mentary distractions  not  involving  any  work,  such  as 


Fig.  7.— Influence  of   Mental    Activity  on  Tapping-time. 


VOLUNTARY 
MOTOR  ABIUTT. 


whistling,  clicking  the  tongue,  or  lighting  a  match,  do 
not  change  the  rapidity.  They  do,  however,  improve 
the  regularity ;  the  curve  is  smoother.  It  is  a  note- 
worthy fact  in  all 
our  mental  life  that 
the  less  attention 
we  pay  to  an  act 
the  more  regular  it 
is. 

The  rapidity  of 
tapping  varies  with 
the  time  of  day. 
The  averages  of 
six  weeks  of  work 


Fia.  8. — Rapidity  of  Tapping  as  Dependent    p-avC   the    followinS" 

results  :  at  8  A.  M. 
the  time  required  for  making  300  taps  was  37.8^  ;  at  10 
A.  M.;  35.0^  ;  at  12  M.,  346^ ;  at  2  P.  M.,  35.5^  ;  at  4 
p.  M.,  33.5^ ,  at  6  P.  M.,  35.1^ . 

It  is  noticeable  that  these  results  corresponded  to 


i8  Thinking,  Feeling,  Doing 


the  habits  of  the  previous  two  years  of  the  person 
experimented  upon ;  these  years  were  spent  in  public 
school  work  with  a  daily  program  beginning  at  8  a.m. 
and  closing  at  4  P.M.,  with  an  hour  and  a  half  inter- 
mission at  noon. 

The  rapidity  of  action  increases  steadily  with  age. 
Measurements  of  tapping- time  on  one  hundred  New 

Haven  school  child- 
ren of  each  age 
from  six  to  seven- 
teen are  shown  in 
Fig.  8.  The  fig- 
ures at  the  left  give 
the  number  of  taps 
in  five  seconds; 
those  at  the  bottom 
the  ages.  The  little 
children  are  very 
slow ;  the  hoys  at  each  age  tap  much  faster  than  the 
girls. 

In  these  experiments  the  children  continued  tapping 
after  the  five  seconds.  After  tapping  thirty-five  seconds 
longer  a  record  was  again  taken.  The  difference  be- 
tween the  two  sets  of  record  tells  how  much  the  child 
lost  owing  to  fatigue.  The  results  are  shown  in  Fig. 
9.  The  figures  on  the  left  give  the  percentage  of  loss  ; 
those  at  the  bottom  the  ages.  Thus,  at  six  years  of 
age  the  boys  lost  y2_J}_  or  23  per  cent,  of  the  original 
number  of  taps. 

The  amount  of  fatigue  was  greatest  at  eight 
years,  and  decreased  with  advancing  age.  It  is 
very     remarkable    that  without  exception    of    a  sin- 


FiG.  9.— Fatigue  in  Tapping  as  Dependent 
on  Age. 


Time  and  Action 


19 


gle  age  the  girls  were  less  fatigued  than  the 
boys.  A  comparison  of  the  two  Figures  suggests 
a  conclusion  as  to  the  impetuosity  of  the  boyish 
character. 

By  connecting  both  the  front  and  back  contacts  of 
the  telegraph  key  in  Fig.  5  a  spark  is  obtained  at  the 
beginning  of  each  up  and  down  movement ;  this  ana- 
lyses the  tap  into  its  two  components.  A  slight  change 
in  the  contacts  and  a  strong  spark  coil  make  it  possi- 
ble to  get  a  record  at  the  end  of  each  movement  also. 
There  are  then  four  sparks  for  each  tap,  one  for  the 
beginning  of  the  down  movement,  one  for  its  end,  one 
for  the  beginning  of  the  up  movement  and  one  for  its 


Fig.  10.— Measuring  the  Simultaneity  in  Actions  of  a  Piano-player. 

end.     The  tap  is  thus  analysed  into  two   movements 
and   two   intervals   of  rest.      For   the   middle   finger 


20  Thinking,  Feeling,  Doing 

the  time  of  each  movement  varies  around  4:2  and  the 
period  of  rest  around  0.8^. 

We  are  justified  in  supposing  that  in  regard  to  a 
single  finger  we  cannot  will  to  do  two  inconsistent 
things  at  the  same  time.  Therefore  the  two  move- 
ments represent  two  successive  acts  of  will,  each  of 
which  required  not  over  4^  to  arise  and  execute  its 
movement.  This  includes  what  we  feel  in  our  mind 
as  the  act  of  will  itself,  the  time  occupied  in  the  bram, 
the  time  of  transmission  along  the  spinal  cord  and  the 
nerves  to  the  muscles  of  the  arm,  the  time  to  arouse 
the  muscle  to  contraction  and  the  time  for  the  entire 
contraction.  At  present  it  seems  hardly  wise  to  at- 
tempt to  isolate  any  of  these  factors,  altliough  it  would 
be  highly  interesting  to  get  the  figures  for  the  mental 
action  alone. 

Let  us  now  inquire  if,  when  we  will  to  move  the 
two  corresponding  fingers  of  the  two  hands  at  the 
same  mon^ent,  they  really  do  move  as  intended  or  if 
one  is  behind  the  other.     To  do  this  we  must  have  two 

keys,  two  spark-coils,  and  two 
metal  points,  one  each  side  of 
the  time-line.  The  plan  of  this 
arrangement  is  shown  in  Fig.  10. 
Fig.  11.— Result  of  the  Ex-  Vv" hen     the    fingers    move,   two 

periment  in  Fi^.  10.     The  i        n       ^i  1.1  i 

ri-htiiand  (upper  dot)  is  sparks  ily  through  the  paper  and 

0.0f).5  of  a  second   behind     .  i  • ,        i    .  j  -rv 

the  left  Gower  dot).  two   whitc  Qots   are   made.     Do 

they  occur  at  the  same  moment  ?    A  specimen   record 
by  a  famous  organist  is  shown  in  Fig.  11. 

Thus  the  will  to  move  both  hands  at  the  same  time 
results  in  moving^  the  two  at  different  times.  A  care- 
ful  investigation  shows  that  sometimes  the  right  pre- 


Time  and  Action 


21 


cedes,  sometimes  the  left,  in  irregular  order.  The 
diflFerence  frequently  amounts  to  1^  and  in  a  condition 
of  fatigue  may  reach  5^.  Such  differences  are  found 
between  all  pairs  of  movements  that  can  be  made  by 
any  parts  of  the  body.  Attention  to  one  movement 
brings  it  ahead  of  the  other.  The  differences  are  not 
due' to  muscular  or  peripheral-nerve  changes,  but  to 
differences  in  the  original  will-impulses. 

For  many  purposes 
it  is  necessary  to  ob- 
tain the  tap  time  with 
out  the  labour  and 
apparatus  involved  in 
the  method  described. 
We  can  do  this  by 
employing  a  tap-coun- 
ter. One  form  of  this 
is  shown  in  Fig.  12  ; 
it  has  to  be  very  care- 
fully made  to  avoid 
the  error  of  failing  to 
count  some  of  the  taps 
and  that  of  counting 
two  when  it  should 
count  one.  The  fin- 
ger can  tap  directly 
on  the  arm  H  or  on 
a  key  connected  with 
the   electromagnet   G  fig.  i2.-Tap  counter, 

which  pulls  H  at  each 

tap.  Each  movement  of  //around  its  axle  /^causes  D 
to  plunge  into  a  notch  of  the  toothed  wdieel  A  whereby 


22  Thinking,  Feeling,  Doing 

A  turns  forward  one  notcli.  A  pointer  (not  shown  in 
the  figure)  on  the  axle  B  passes  over  a  dial  and  shows 
liow  many  taps  have  been  made. 

The  person  to  be  experimented  on  is  told  to  tap 
as  rapidly  as  possible,  or  slowly,  or  rhythmically  as  the 
case  may  be,  for  fifteen  seconds;  this  divided  by  the 
number  of  taps  indicated  gives  the  average  tap-time. 
To  measure  the  fatisrue  a  record  is  made  before  the 
work  is  performed,  and  again  afterward ;  the  percent- 
age of  loss  is  taken  as  the  fatigue-index.  The  arrange- 
ment makes  it  easy  to  tell  when  children  become 
fatigued,  whether  a  lesson  is  too  long  or  too  difficult, 
etc. 

In  some  experiments  with  this  apparatus  both  in- 
dex fingers  and  great  toes  were  tested  as  to  their  great- 
est rapidity  in  tapping ;  then  the  right  great  toe  was 
practised  daily  for  ten  to  twenty  days.  Thereafter  all 
four  digits  were  tested  as  before ;  there  w^as  a  gain  in 
rapidity  not  only  in  the  toe  that  had  been  practised 
but  also  in  each  of  the  other  diii;its.  Practice  in  one 
activity  had  thus  improved  other  activities.  The  phe- 
nomenon may  be  called  "cross-education";  we  shall 
refer  to  this  remarkable  fact  again. 

Some  of  the  fundamental  phenomena  of  mind  can 
be  demonstrated  by  simply  tapping  with  the  finger  on 
a  table.  Tell  a  person  to  tap  as  rapidly  as  he  can 
and  to  keep  it  up  under  all  circumstances.  You  will 
notice  that  during  the  first  few  seconds  he  gains  in 
rapidity — the  gain  of  "  w^arming  up,"  which  means 
that  his  nervous  adjustments  become  better  and  his 
attention  becomes  better  concentrated.  You  next 
notice  that  he  taps  less  and  less  rapidly  but  that  soon 


Time  and  Action  23 

he  taps  fast  again ;  this  repeats  itself  over  and  over, 
the  fast  portion  becoming  shorter  and  the  slow  por- 
tion lons^er.  Here  we  have  an  illustration  not  only 
of  the  fact  of  mental  fatigue,  but  also  of  the  fact 
that  fatigue  proceeds  by  waves  of  loss  and  recovery. 
Finally  the  person  will  stop  as  if  paralysed.  But  you 
tell  him  he  must  go  on  tapping;  he  will  do  so  but 
will  again  stop,  again  recover,  etc.  This  is  also  an 
illustration  of  the  course  of  fatigue. 

Again,  a  person  taps  as  rapidly  as  he  can  ;  suddenly 
tell  him  to  tap  still  faster;  he  will  do  so,  thus  illus- 


sr- 

UA 

B^                           C0| 

A 

«r\ 

/    1  X                                                 1 

V 

V 

^                            II 

Jffi 

H  ^^' 

Z. 

— \ 

Fig.  13.— Experimental  Writing-board. 


trating  the  principle  that  we  have  a  reserve  of  energy 
which  can  be  called  forth  by  the  proper  stimulus. 
The  slowing  of  tapping  during  mental  work,  the  in- 
crease of  regularity  during  distracted  attention,  etc., 
can  all  be  demonstrated  in  the  same  way. 

It  is  often  desirable  to  study  how  time  is  distributed 
in  performing  an  act.     As  an  illustration,  let  us  con- 


24  Thinking,  Feeling,  Doing 

sidcr  a  mctliod  of  registering  the  movements  used  in 
writing.  The  board  in  Fig.  13  is  covered  with  a 
sheet  of  metal  A.  A  piece  of  paper  ^covered  with  soot 
(smoked  while  on  a  drum  and  then  removed)  is  placed 
on  it.  It  is  connected  with  a  wire  (7 from  the  spark  coil. 
The  other  wire  from  the  coil  leads  to  the  pen  D  in 
a  metal  holder  covered  with  rubber.  A  vibrating  elec- 
tric fork  (Fig.  3)  is  placed  in  the  primary  circuit  of 
the  spark  coil ;  consequently  a  spark  flies  from  D 
through  the  smoked  paper  at  each  vibration  of  the 
fork.  A  person  is  asked  to  write  letters,  words  and 
sentences  on  the  smoked  paper  with  the  pen  ;  the  sparks 
from  the  pen  make  white  dots  on  the  line  at  each  hun- 
dredth of  a  second.  When  the  pen  moves  rapidly,  the 
sparks  are  farther  apart.  In  the  illustration  we  see 
them  grouped  (slower  movement)  whenever  the  pen 
makes  a  change  in  direction.  We  also  notice  that 
tliey  are  farther  apart  when  no  effort  is  made  to  con- 
nect letters.     The  conclusions  are  self-evident. 

The  diagram  B  at  the  top  of  the  board  is  for  judg- 
ing the  slant  of  the  lines.  It  was  found  that  hor- 
izontal movements  to  the  right  and  left  were  most 
rapid,  that  the  slant  downward  and  to  the  left  was 
next  best,  and  upward  to  the  right  nearly  as  good. 
Vertical  and  backhand  writing  were  slower ;  the  persons 
tested  had  first  learned  to  write  witli  a  slant;  it  still 
remains  unsettled  how  persons  who  have  learned  ver- 
tical writing  at  school  would  act. 


CHAPTER  III 


REACTIOX-TIME 


WHEN  you  signal  to  the  car  conductor  to  stop, 
he  reacts  by  pulling  the  bell-strap,  the  driver 
reacts  to  the  sound  of  the  bell  by  pulling  the  reins 
and  the  horses  react  by  coming  to  a  rest.  By  reaction, 
then,  we  will  understand  action  in  response  to  a  sig- 
nal. The  time  between  the  moment  of  the  signal  and 
the  moment  of  the  act  is  known  as  the  reaction-time. 


Fig.  14.— a  Series  of  Reactions. 

Is  there  any  such  time?  Quick  as  thought — that 
must  be  pretty  quick.  Let  a  number  of  persons  stand 
in  Indian  file  as  if  about  to  march ;  each  one  places 
his  right  hand  on  the  head  (or  shoulder)  of  the  person 
in  front.  Bend  the  file  around  till  a  complete  circle  is 
formed  with  every  right  hand  on  the  head  of  the  one 
in  front.     One  of  this  file  we  will   call   the   experi- 

25 


26  Thinking,  Feeling,  Doing 

menter ;  in  his  left  hand  he  holds  a  watch — preferably 
a  stop-watch.  All  the  rest  close  their  eyes.  The  in- 
struction is  given  :  wheneveryou  feel  a  sudden  pressure 
from  the  hand  on  your  liead,  you  must  immediately 
press  the  head  of  the  person  in  front.  When  the 
seconds-hand  of  the  watch  is  at  the  beginning  of  a  min- 
ute, the  experimenter  presses  the  head  of  the  one  in 
front,  he  presses  that  of  the  next  in  front,  and  so  on. 
The  pressure  thus  passes  all  around  the  group  and 
finally  comes  back  to  the  experimenter.  At  the 
moment  he  feels  the  pressure  he  notes  how  many 
seconds  have  passed.  Suppose  there  were  ten  persons 
in  the  circle  and  the  watch  has  gone  three  seconds ; 


Fig.  15,— Chain-reaction. 

then  three  seconds  is  the  time  required  for  ten  acts  in 
response  to  a  signal.  The  average  time  for  one  reaction 
is  obtained  by  dividing  the  number  of  seconds  by  the 
number  of  persons ;  thus,  in  this  case  the  reaction- 
time  would  be  Y^-jj  of  a  second,  or  0.3^. 


Reaction-Time  27 

It  takes  time,  then,  to  react.  A  hundred  years  ago 
people  did  not  know  this.     And  thereby  hangs  a  tale. 

Astronomers  have  to  record  the  moment  of  the  pas- 
sage of  a  star  across  lines  in  a  telescope.  In  l795  the 
British  astronomer  royal  found  that  his  assistant, 
working  with  another  telescope  at  the  same  time,  was 
making  his  records  too  late  by  half  a  second.  Later 
on,  this  difference  amounted  to  0.8^ .  This  difference 
was  large  enough  to  seriously  disturb  the  calculations, 
so  the  poor  fellow  lost  his  place  for  the  sake  of  eight- 
tenths  of  a  second. 

Many  years  later  two  famous  astronomers  were  ob- 
serving the  stars  together  and  recording  their  passages 
across  the  telescope.  Strange  to  say,  one  was  steadily 
behind  the  other.  Now  it  would  not  do  to  make  ac- 
cusations against  a  noted  astronomer ;  this  set  people 
to  thinking.  One  of  the  astronomers  went  to  a  third 
astronomer  and  again  there  was  a  disagreement. 
Finally,  after  more  experience,  astronomers  in  general 
reached  the  conclusion  that  everybody  disagreed  with 
everybody  else.  Moreover  men  who  disagreed  in  one 
way  at  one  time  would  be  likely  to  disagree  differently 
at  another  time ;  so  that  a  man  did  not  even  agree 
with  himself.  As  this  was  evidently  not  the  fault  of 
the  star,  the  conclusion  was  finally  reached  that  each 
person  had  a  peculiar  error  of  his  own.  This  was 
called  by  the  queer  name,  '*  personal  equation.  "  The 
British  astronomer,  who  did  not  suspect  that  he  him- 
self might  be  incorrect  was  perhaps  no  nearer  right 
than  his  assistant.  At  any  rate,  the  actual  time  of 
the  star  differed  from  the  recorded  time.  These 
observations  led  to  a  search  for  the  reaction-time. 


28  Thinking,  Feeling,  Doing 


If  we  could  get  the  star  to   make  the  first   dot 
on    the    time-line   (Fig.  4),    and   the   astronomer   to 

make  the  second  one, 
we  could  measure 
his  r  eacti  on-tim  e. 
This  was  attempted 
by  using  artificial 
stars  with  electric 
connections.  Finally 
an  entire  technique  of 
reaction-time  experi- 
ments was  developed. 
To  make  careful  ex- 
periments on  reaction 
the  person  is  placed 
in  a  reaction-room 
where  he  will  not  be 
disturbed.  The  best 
reaction-room  is  an 
"isolated  room," 
whose  thick  walls  and 
double  doors  keep  out 
all  sound  and  light. 

Fig.  16.-In  the  Reaction-room.  When  a  pcrsOn    locks 

himself  in,  he  has  no  communication  with  the  outside 
world  except  by  telephone. 

The  person  in  the  reaction-room — sits  comfortably 
with  the  telephone  at  his  ear  and  with  an  electric 
reaction-key  (Fig.  17)  in  his  hand  (the  ordinary 
telegraph  key  may  be  used).  The  forefinger  is  placed 
in  the  hole  of  the  smaller,  or  movable,  slide, 
and   the   thumb   is   placed    in    the    hole   or    against 


Reaction-Time 


29 


the  hook  of  the  lower,  or  adjustable,  slide.  Flexi- 
ble wires  lead  to  the  post  at  the  top  and  to  the  movable 
slide.  The  hand  is  placed  in 
any  convenient  position,  and 
the  thumb  and  finger  are  held 
apart.  The  wires  lead  to  a 
spark  coil  in  a  distant  record- 
ing room. 

A  double  key  is  arranged  in 
the  recording-room  so  that 
when  it  is  pressed  a  sound  is 
sent  through  the  telephone  in 
the  reaction-room  and  at  ex- 
actly the  same  instant  a  spark 
is  made  on  the  time-line  on  the 
drum.  The  moment  the  sound 
is  heard  by  the  person  experi- 
mented upon,  he  moves  the 
finger  in  the  reaction-key ; 
thus  a  second  spark  is  made  on  the  time-line.  A 
record  similar  to  that  of  Fig.  4  is  obtained ;  the  num- 
ber of  waves,  however,  will  depend  on  the  particular 
person,  the  particular  sound,  etc. 

To  illustrate  how  psychological  results  are  obtained 
from  reaction-times,  let  us  suppose  ten  experiments  to 
give  the  results  in  the  first  column  of  the  example  on 
page  30.  Adding  the  results  and  dividing  by  their 
number,  we  get  the  average  reaction-time,  0.1 42^  We 
now  find  the  difference  between  this  averasre  and  each 
of  the  original  results;  these  differences  are  then  aver- 
aged to  find  the  "average  variation."  In  this  case  it  is 
0.0076«  or,  let  us  say,  0.008^ 


Fig.  17.— Reaction-key. 


30  Thinking,  Feeling,  Doing 

0.1G2S  0.020 

0.145  3 

0.157  15 

0.136  6 

0.131  11 

0.140  2 

0.135  7 

0.139  3 

0.139  3 

0.136  6 


0.1420  0.0076 


The  average  reaction-time  includes  the  time  taken 
by  the  sound  waves  to  affect  the  ear,  the  time  for  con- 
ducting the  nerve  impulses  to  the  brain,  the  time 
occupied  by  a  series  of  brain  processes,  the  time  for 
conducting  the  nerve  impulses  to  the  hand,  and  the 
time  for  setting  the  muscles  to  work.  From  physio- 
logical experiments  it  is  known  that  very  little  time  is 
required  for  the  first  and  last  two  ;  the  main  part  is 
taken  by  the  brain  processes.  Somewhere  in  connec- 
tion with  the  brain  processes  there  occur  the  mental 
acts  of  perceiving  the  sound  and  willing  to  move  the 
hand  ;  the  reaction-time  thus  includes  the  time  of  per- 
ception and  volition.  The  following  illustrations  of 
differences  in  reaction-time  are  due  to  changes  in 
perception  and  volition. 

We  notice  first  that  the  reaction-time  is  longer  and 
less  constant  for  the  first  few  experiments  ;  this  agrees 
with  the   observations   on    tapping   (p.   16).     Let   us 


Reaction-Time 


31 


repeat  these  experiments  a  number  of  times  and  take 
more  than  ten  each  time.  Then  let  us  average  all  the 
first  ones  separately,  all  the  second  ones  likewise,  etc. 


^^s/ye      Reaction    T/mes 


ra 


ct 


ic 


;      ::     '■      '' 


■■      :: 


Fig.  18.— Curve  of  Practice. 


Fig.  18  shows  lines  erected  proportional  to  the  succes- 
sive averas^e  times.  The  decrease  from  the  first  aver- 
age  time  we  may  term  the  "gain  by  practice  "  ;  a  line 


^s, 


^e 


'ays 


ab 


■■:      ■■      '■■     :■. 


Fig.  19.— Curve  of  Habit. 


showing  the  amount  of  this  gain  will  be  the   "curve 
of  practice." 


32  Thinking,  Feeling,  Doing 

Let  us  now  average  all  the  results  for  each  day  • 
Fig.  19  shows  the  result.  The  decrease  in  time  for 
each  succeeding  day  may  be  called  the  "  gain  by 
habit ; "  a  line  expressing  this  will  be  the  "  curve 
of  habit." 

We  now  make  two  sets  of  experiments  under 
exactly  the  same  conditions,  but  in  one  set  we  warn 
the  subject  about  two  seconds  beforehand  when  to 
expect  the  sound  whereas  in  the  other  we  tell  him  to 
watch  all  the  time.  The  results  show  a  somewhat 
longer  reaction  in  the  second  set  and  a  far  larger 
average  variation;  for  example,  0.159^  and  0.047^ 
as  contrasted  with  0.142^  and  0.008^^.  We  find 
this  to  be  always  the  case,  and  we  established  the 
principle  that  a  state  of  relaxation  with  a  call  to  at- 
tention just  before  something  is  to  be  done  enables  us 
to  act  somewhat  more  quickly  and  far  more  regularly 
than  an  attempted  state  of  continuous  attention.  In 
the  former  state  we  attain  maxima  of  energy  by  relax- 
ing between  times ;  in  the  latter  we  keep  at  a  dull 
level.  It  is  on  a  small  scale  the  same  principle  of 
intermittent  activity  and  recuperation  that  is  involved 
in  sleep.  Distraction  of  attention  likewise  produces  a 
longer  average  time  and  a  far  larger  average 
variation. 

Persons  may  be  divided  into  groups  according  to 
their  reaction- times.  Four  types  of  persons  are  famil- 
iar to  the  physician.  The  self-controlled  man  of 
abundant  vitality  reacts  quickly  and  regularly ;  the 
phlegmatic  or  relaxed  man  responds  regularly  but 
slowly;  the  excitable  man  of  strong  vitality  gives 
quick  but  variable  responses ;  the  neurasthenic  weak- 


Reaction-Time 


33 


ling  is  excessively  irregular  and  his  average  reaction- 
times  are  slower  than  normal. 

Conditions  of  disease  also  show  themselves  in  the 
reaction-times.  In  the  first  stages  of  intoxication  by 
alcohol  the  reactions  may  be  quicker  and  more  regu- 
lar but  they  soon  become  slower  and  very  irregular ; 
in  an  attack  of  alcoholism  where  the  person's  nerves 
are  on  edge  so  that  he  cannot  sleep  and  feels  himself 
on  the  verge  of  delirium  tremens,  his  average  reaction- 
time  is  very  short  and  his  regularity  is  remarkably 
good. 

The  reaction-time  depends  somewhat  on  the  kind  of 
sensation.  For  noises  it  is  a  trifle  shorter  than  for 
tones.  For  example,  a  person  wdio  reacts  to  a  noise  in 
11^  will  take  perhaps  15-^  for  a  tone.  Even  the  whistle 
of  a  locomotive  is  not  so  conducive  to  a  quick  jump 
by  the  passengers  on  the  platform  as  a  sudden  escape 
of  steam. 

A  particular  case  of  reaction  to  sound  is  found  in 
starting  a  race.  In  short-distance,  or  sprint,  racing  the 
time  required  for  the 
reaction  is  a  very  im- 
portant factor.  The 
starter's  pistol  is  fired 
and  the  racers  are  off, 
but  the  man  with  a 
very  short  reaction- 
time  will  have  gained 
a  respectable  fraction 
of  a  second  over 
the  other.  To  measure  this  reaction-time  an 
electric   contact    is  put  on    the  end   of  the   starter's 


Fig.  20.— The  Pistol-key, 


34  Thinking,  Feeling,  Doing 


pistol.     The  arrangement  is  shown  in  Fig.  20.     The 

.  firing  of  the 

pistol  causes 
the  wing  to  fly  back 
and  break  an  electric 
circuit,  thus  making  a 
record.  A  runner's 
key  of  the  kind  shown 
in  Fio^.  21  is  attached 
to  the  runner  by  a 
thread.  The  start  of  the  runner  jerks  and  breaks  the 
thread;  tliis  moves  the  lever  and  makes  another 
record.     It  is  noticeable  that  long-distance  runners  are 


Fig.  21.— The  Runner's  Key. 


Fig.  22. — Measuring  a  Runner's  Reaction-time. 

very    much    slower   than    sprint-runners    who    prac- 
tise quick  starting ;  this  shows  that  the  reaction- time  can 


Reaction-Time  35 

be  reduced  by  practice.  The  reaction-time  seems  to  be 
lono"er  where  the  whole  body  has  to  be  started  than 
where  only  a  finger  is  moved  ;  the  mass  to  be  moved 
thus  seems  to  have  an  influence  on  the  time.  In  some 
races  the  pistol  has  gone  off  and  the  photograph  has 
been -made  of  the  runners  before  they  have  reacted. 

The  reaction- 
time  to  touch  can 
be  found  by  us- 
ina:  the  instru- 
ment  shown  in 
Fig.  23.  The  flex- 
ible     conductors  Fio.  2:3.-The  Touch-key. 

carry  the  current  through  the  screws  of  this  touch 
key  and  then  through  the  reaction-key.  The  per- 
son experimented  upon  closes  his  eyes.  Some  one 
takes  the  toucli-key  and  touches  him,  whereupon  he 
reacts  by  moving  his  finger.  Both  keys  make  records 
on  the  drum. 

A  weak  touch  is  answered  by  a  slower  reaction  than 
a  moderately  strong  one.  As  tlie  touch  becomes  stronger 
the  reaction-time  decreases,  but  when  it  becomes  very 
strong  the  time  is  a2:ain  lengthened. 

To  experiment  on  the  reaction-time  for  temperature- 
sensations  a  metal  ball  is  screwed  on  the  touch-key 
in  place  of  the  rubber  tip.  The  ball  is  heated  or 
cooled  as  desired.  The  reaction-time  for  cold  is  some- 
what shorter  than  that  for  hot,  and  both  are  longer 
than  for  touch.  For  example,  the  figures  for  one  ex- 
perimenter were :  touch,  11^  ;  cold,  122  ;  hot,  13  2. 

The  reaction-time  to  light  may  be  found  by 
using  an  electric  flasli.     The  intensity  of  the  light  has 


3^  Thinking,  l^eeling,  Doing 

a  very  great  influence.  A  very  weak  light  might  give 
332,  while  the  strong  one  would  give  20-2  for  the 
same  person. 

This  interval  renders  it  possible  for  the  photographer 
to  get  j)erfectly  natural  flash-light  pictures.  The  flash 
goes  off,  the  picture  is  taken,  and  all  is  again  dark 
in  a  couple  of  hundredths  of  a  second.     But  sucli  a 


REACTION  TIME 


6         7  8  9         iO         II         IZ         15         /*        IS        /6       17 

Fig.  24.— Reaction-time  Decreases  with  Age. 


small  time  is  quicker  than  the  reaction-time  and  so  the 
whole  is  done  before  the  person  can  move. 

Children  become  steadily  quicker  as  they  grow 
older.  The  results  of  the  New  Haven  measurements 
are  shown  in  Fig.  24.  The  figures  at  the  left  indicate 
the  number  of  hundredths  of  a  second  required  for 
reaction  to  sight ;  those  at  the  bottom  the  ages.  Boys 
are  much  quicker  than  girls  at  each  age — that  is,  in 
simple  reaction ;  how  they  compare  in  quickness  of 
thought  will  be  told  in  the  following  chapter. 


CHAPTER  TV 

THIXKING-TIME 

ONE  of  the  fundamental  processes  of  thought  is 
recognition.  To  determine  the  time  of  recog- 
nition the  subject  reacts  on  one  occasion  just  as 
quickly  as  he  can,  without  waiting  to  notice  what  he 
is  reacting  to.  In  popular  phrase,  he  hits  back  with- 
out waiting  to  know  what  struck  him.  Recognition 
cannot  be  said  to  be  present.  On  the  next  occasion 
he  fully  recognises  what  he  hears,  sees,  or  feels  before 
he  reacts.  The  difference  in  time  between  these  two 
cases  gives  the  recognition-time.  Properly  speaking, 
the  former  reaction  would  be  the  truly  simple  reaction, 
but  this  distinction  is  often  overlooked  and  both 
kinds  are  then  lumped  together.  Experiments  on 
one  subject  gave  the  following  recognition-times :  for 
colour  3^ ;  for  a  letter,  52  ;  for  a  short  word,  62. 

By  using  a  rapid  drop-shutter  with  adjustable  open- 
ing we  can  find  the  briefest  exposure  requisite  for  us 
to  recognise  an  object.  The  time  of  exposure  can 
also  be  termed  the  "recognition-time."  The  following 
results  are  of  interest. 

A  single  figure,  such  as  a  triangle  or  a  square,  is 
recognised  as  quickly  as  a  simple  colour.  We  can 
grasp  enough  of  a  triangle   to   recognise    it  without 

37 


38  Thinking,  Feeling,  Doing 

attending  to  details ;  a  three-cornered  figure  is  as  simple 
as  a  colour  when  nothing  but  its  corneredness  is  no- 
ticed. A  single  letter  takes  the  same  time  as  a  short 
word.  The  total  impression  of  a  well-known  object  is 
so  familar  to  us  that  we  need  no  more  divide  it  into  its 
parts  in  order  to  distinguish  it  than  we  do  in  the  case 
of  a  simple  colour.  In  reading  we  do  not  divide  the 
word  into  its  letters,  we  grasp  the  word  as  a  whole  by 
a  single  thought. 

The  various  letters  of  the  alphabet  require  different 
times  for  recognition.  There  are  differences  for  let- 
ters of  different  sets  of  type;  they  vary  from  0.6^ 
(0.006«)  to  SJS"  (  0.05«).  The  following  sets  of  letters 
are  arranged  in  the  order  of  time  required. 


Good. 


Fair. 


Poor. 


mwdqvyjpkfblighrxtov  ane  s  c  z 


mwp  qv  ykbdjrlonighu 


dpqmyknw 


ogvx  h  bjlia 


atfsxzce 


tuzrscfe 


A  German  requires  1^  to  22  more  time  to  recog- 
nise a  letter  of  his  antiquated  alphabet,  for  examjile, 
in,  than  to  recognise  a  letter  in  the  Latin  type,  w. 
But  in  reading  words  no  more  time  is  required  to 
recognise  the  word  in  either  case.  The  twists  and 
tails  of  the  old  letters  caused  a  loss  of  time  in  recog- 
nising a  single  letter,  but  in  grasping  the  words  only 
the  main  features  received  attention  anyway. 


Thinking-Time  39 

Another  of  the  fundamental  processes  of  thought  is 
discrimination :  Is  it  white  or  black,  loud  or  weak, 
hot  or  cold?  Can  we  measure  the  time  required  for 
discrimination  ? 

Suppose  that  the  subject  of  the  experiment  is  to  dis- 
criminate between  two  different  tones.  In  addition  to 
the  arrangement  described  on  page  29  we  require  two 
tuning-forks  of  different  pitch.  The  sound  is  sent  by 
telephone  as  before.  The  person  is  told  not  to  react 
till  he  has  recognised  which  tone  he  hears.  Some- 
times one  tone  is  sent,  sometimes  the  other.  If  we  de- 
termine the  person's  reaction-time  for  a  single  tone, 
where  he  knows  that  only  one  tone  is  used,  and  also 
the  reaction-time  with  discrimination  between  two  tones, 
we  are  justified  in  subtracting  the  former  from  the  lat- 
ter, and  calling  the  result  the  "  discrimination  time  "  for 
two  tones.  In  a  similar  manner  the  discrimination- 
time  for  three,  four,  or  more  tones  can  be  measured. 

The  discrimination-time  for  sight  can  be  illustrated 
by  Geissler  tubes  filled  with  different  gases  so  tliat 
when  an  electric  current  is  sent  through  them  they 
show  different  colours.  An  induction-coil(or  spark-coil) 
is  fitted  up  so  that  the  current  can  be  seen  through  any 
tube  at  pleasure.  To  get  the  simple  reaction-time  one 
tube  alone,  e.  g.,  a  red  tube,  is  used,tlie  time  between  the 
flash  and  the  reaction  being  measured  as  before.  Then 
two,  three,  etc.,  are  used,  just  as  described  for  tones. 
Ordinary  times  for  discrimination  can  be  represented  by 
the  following  specimens ;  for  two  objects,  8^ ;  for 
three,  14^  ;  for  four  or  fi\^e,  15-2". 

The  next  element  of  thought-life  to  be  considered  is 
choice,     The  Geissler  tubes  can  be  ver^  conveniently 


40  Thinking,  Feeling,  Doing 

used  for  experiments  on  choice-time.  The  subject 
places  his  five  fingers  on  a  five-knobbed  telegraph  key. 
When  he  sees  the  red  light  he  is  to  press  his  thumb  ; 
when  he  sees  the  yellow  he  is  to  press  his  forefinger, 
and  so  on.  There  are  thus  five  objects  for  discrimination 
and  five  movements  among  wliich  to  choose.  Of  course 
the  time  is  much  lenothened.     If  we  know  the  dis- 

o 

crimination-time  and  reaction-time  for  five  colours,  we 
can  subtract  these  from  the  total  time  with  choice,  thus 
getting  the  choice-time  for  five.  It  is  evident  that  the 
choice-time  for  two,  three,  four,  six,  or  more  objects  can 
be  similarly  found.  One  subject  gave  a  choice-time  of 
8^  for  two  fingers,  with  steady  increase  up  to  40^  for 
ten  fingers. 

After  some  practice  with  the  same  fingers  for  the 
same  colours,  the  act  of  choice  gradually  falls  out  and 
the  movement  becomes  associated  to  the  colour.  The 
action  becomes  more  and  more  "automatic." 

The  time  of  discrimination  and  choice  combined  can 
be  obtained  from  a  group  of  persons  without  any  other 
apparatus  than  a  watch.  The  persons  of  the  group 
stand  in  a  ring,  as  shown  in  Fig.  15,  each  with  his  hand 
on  his  neighbour  s  head.  In  the  first  place,  the  simple 
reaction-time  is  measured  by  giving  the  head  a  slight 
push  and  sending  the  push  all  around  the  circle,  as 
described  on  page  25.  "  Next  time,"  says  the  experi- 
menter, "  each  of  you  will  receive  a  slight  push  on  the 
head  either  forward  or  backward.  You  are  to  send  the 
push  along  in  the  same  way." 

The  experiment  is  made  three  or  four  times,  some- 
times with  a  forward  push,  sometimes  v/ith  a  backward 
one.     Each  person,  not  knowing  what  he  is  to  receive, 


Thinking-Time 


41 


will  be  obliged  to  discriminate  and  then  choose  the 
appropriate  movement  of  the  hand.  By  subtracting 
the  simple  reaction-time  from  this  last  result,  the  time 
for  discrimination  and  choice  for  two  things  is  ob- 
tained. Then  the  experiment  is  repeated  with  three 
movements :  right,  left,  or  forward.  Then  with  four  : 
right,  left,  forward,  or  backward.  The  time  will  be 
found  to  grow  longer  as  the  number  increases. 

The  time  of  association  of  ideas,  which  is  what  is 
usually  meant  by  "  association- time,"  is  best  measured 
by  calling  out  words  or  showing  pictures  to  some  one 
who  is  to  tell  what  he  associates  to  each.  For  exam- 
ple, I  call  out  "  house  "  and  you  say  "  street" 

A  peculiar  mouth-piece  (Fig.  25)  is  placed  before 
the  transmitter 
in  the  recording- 
room  and  a  some- 
what similar  one 
in  the  reaction- 
room.  Theex- 
perimenter  shouts 
some  word,  e.  g., 
"glass."  This 
causes  the  thin  plate 
in  the  mouth-key  to 
rattle  and  make  a 
spark  record  on  the 
drum.  At  the  same 
moment  the  subject 
hears  the  word  in  the  telephone  at  his  ear.  He  shouts 
back  what  he  first  thinks  of,  e.  ^.,  "water."  This 
makes  a  similar  record.     The  total  time  between  the 


Fig.  25— The  Voice-key. 


42  Thinking,  Feeling,  Doing 

two  records  less  the  discrimination-time  and  choice- 
time  will  give  the  association-time. 

The  associations  may  be  of  various  kinds.  In  "  free  " 
association,  tlie  subject  thinks  of  wliatever  he  pleases. 
The  time  for  free  association  can  be  put  in  the  neigh- 
bourhood of  50^  to  100 2"  according  to  circumstances. 

In  a  "forced"  association  the  subject  is  allowed  to 
associate  only  objects  bearing  certain  relations  to  the 
object  presented.  Thus,  whenever  he  hears  the  name 
of  a  country  he  must  name  one  of  its  cities.  In  such 
a  case  he  has  a  moderate  range  of  association.  In  a 
strictly  forced  association  there  is  no  freedom.  Thus, 
whenever  the  name  of  a  person  is  mentioned,  his  native 
land  must  be  associated.  As  specimen  results  we  can 
give  the  following  association-times :  translation  from 
one's  own  language  to  one  a  trifle  less  familiar,  60^  to 
90^^;  giving  the  succeeding  month  of  the  year,  70-^ 
to  80-2;  simple  addition  of  two  figures,  60^  to  752; 
simple  multiplication  of  two  figures,  802  to  1002. 

A  particular  form  of  association  is  found  in  logi- 
cal judgments.  In  fact,  many  of  the  forced  associations 
are  really  abbreviated  logical  j  udgments.  Suppose  it  to 
be  required  to  associate  the  whole  when  a  part  is  given, 
e.  g.^  given  "  root,"  associated  "  tree  "  ;  this  is  simply  a 
practical  abbreviation  of  "a  root  ispart  of  a  tree."  More 
difficult  cases  can  be  devised.  It  holds  good  as  a  general 
rule  that  in  actual  thinking  the  forms  of  logical  thought 
become  forced  associations. 

The  visit  of  several  expert  swordsmen  to  Yale  fur- 
nished the  opportunity  for  some  experiments  on  their 
rapidity  in  some  of  the  fundamental  movements  of 
fencing. 


Thinking-Time 


43 


The  first  experiment  included  a  determination  of  the 
simple  reaction-time  and  of  the  time  of  muscular  move- 
ment. The  fencer  stood  ready  to  lunge,  with  the  point 
of  the  foil  resting  to  one  side  against  a  metal  disk  (Fig. 
26).    A  flexible  conducting  cord,  fastened  to  the  handle 


FiG.  26.— Measuring  Mental  and  3Iuscular  Time  in  Fencing. 

of  the  foil,  hung  in  a  loop  from  the  back  of  the  neck.  A 
large  metal  disk  was  placed  directly  in  front  of  the  fenc- 
er at  a  distance  of  7d^^.  Just  above  this  disk  was  a 
flag  held  on  a  foil  by  an  operator  standing  behind  it. 
A  movement  of  the  flag  was  the  signal  upon  which 
the  lunge  was  executed. 

The  spark  method  of  recording  was  so  arranged  that 
the  primary  circuit  passed  through  the  electric  switch, 
a  spark-coil,  the  flexible  conducting-cords,  the  foils,  and 
either  one  of  the  two  disks.     Every  make  and  break  of 


44  Thinking,  Feeling,  Doing 

this  circuit  made  a  spark  record  on  the  drum.  As  long 
as  the  foils  rested  against  the  disks  the  current  was 
closed.  The  movement  of  the  flag-foil  broke  the  cir- 
cuit for  an  instant,  making  a  record  of  the  moment  of 
siirnal.  The  first  movement  of  the  fencer's  foil  broke 
the  circuit  again  at  the  small  disk,  making  a  record  of 
the  moment  of  reaction.  The  striking  of  the  foil  against 
thelarge  disk  made  a  third  record.  The  time  between  the 
first  and  second  records  gave  the  simple  reaction-time; 
that  between  the  second  and  third  gave  tiie  time  of 
movement  through  the  given  distance.  About  ten 
experiments  were  made  on  each  person. 

p 

A 


Fig.  27. — Apparatus  for  Measuring  Rapidity  of  Thought  and  Action. 

In  the  second  experiment  the  flag-foil  was  moved 
in  various  directions.  The  point  of  the  foil  rested 
against  the  small  disk.  The  movement  of  the  flag  in 
any  way  was  the  signal  for  a  corresponding  movement  of 
the  foil.  Acts  of  discrimination  and  choice  were  thus 
introduced  in  the  reaction- time.  The  movement  of 
the  foils  gave  records  as  before.  The  time  required 
can  be  considered  as  reaction- time  with  discrimination 
and  choice. 

The  persons  experimented  upon  included  a  fencing 
master  J.  (a  professional  athlete),  three  phj-sicians 
H.,  E.,  and  0.,  and  a  business  man,  S.  (all  expert  ama- 
teur fencers),  and  two  college  professors,  L.  and  W. 
For  the  muscular  movement  the  records  in  hundredths 


Thinking-Time 


45 


of  a  second  were :  for  J.,  27  ;  0.,  E.,  S.,  and  W.,  29  to 
32;  forL.  and  W.,  52  to  57.  The  superior  quickness 
of  trained  fencers  is  apparent.  For  the  simple  reaction- 
time  the  results  were  forE.,  W.,  and  H.,  17-19;  for  L., 
J.,  and  S.,  23  ;  and  for  0.,  26.  The  trained  fencers  thus 
showed  no  superiority  over  the  untrained  persons,  L. 
and  W.  For  the  reaction  with  discrimination  and  choice 
the  results  were  for  H.,  L.,  and  W.,  22-25 ;  for  J.  and 
E. ,  29-30  ;  for  S.  and  0. ,  36.  The  two  college  professors 
and  one  physician  were  thus  quicker  than  the  rest. 

In  order  to  study  the  quickness  of  movements  of 
the  arm  we  use  the  apparatus  shown  in  Fig.  27.  A  hori- 
zontal brass  bar  carries  on  it  three  adjustable  blocks,  A, 
B,  and  C.     The  block  A  has  a  flag  which  maybe  sud- 


FiG.   :2>>.— .Measuring  lur.v  iiapidiy  a  i'ugilist  Thinks  and  Acts. 

denly  jerked  to  one  side  by  a  thread.     The  other  blocks 
have  light   bamboo  sticks  projecting  upward.     The 


4^  Thinking,  Feeling,  Doing 

whole  arrangement  as  used  on  a  pugilist  is  shown  in 
Fig.  28.  The  boxer  takes  his  position  and  places  his 
fist  just  behind  the  stick  at  C.  At  the  moment  the 
flag  moves  he  is  to  strike  straight  out.  The  apparatus 
is  connected  with  the  spark-coil  and  the  recording  drum. 
The  flag  is  jerked  ;  this  makes  a  spark  on  the  time- 
line. The  boxer  strikes,  knocking  down  both  sticks. 
Each  stick  makes  a  spark  also.  We  thus  have  three 
sparks  on  the  time-line.  The  time  between  the  first  and 
the  second  gives  the  simple  reaction  of  the  boxer ;  that 


Fig.  29.— Measuring  how  Fast  a  Dog  Thinks. 


between  the  second  and  the  third  gives  the  time  re- 
quired for  the  fist  to  travel  the  distance  between  the 
two  sticks. 


Thinking-Time  47 

The  boxer  is  next  told  that  the  flag  will  be  jerked 
to  the  right  or  left  in  irregular  order  and  he  is  to 
punch  only  when  it  goes  to  the  left.  He  is  thus 
obliged  to  discriminate  and  choose.  Sparks  are  ob- 
tained as  before,  but  the  time  between  the  first  two 
dots  is  longer  because  two  extra  mental  acts  are 
included. 

It  is  possible  to  extend  these  experiments  to  ani- 
mals. The  arranD^ement  for  measurino-  the  discrimina- 
tion-time  of  a  dog  is  shown  in  Fig.  29.  The  dog  is 
fastened  to  an  electric  key  on  the  wall.  Two  magnetic 
shutters  stand  on  the  floor.  To  get  the  dog's  simple 
reaction-time  a  piece  of  meat  is  placed  behind  one  of 
the  shutters.  The  dog  is  to  see  this  done;  this  secures 
maximum  attention  and  lets  him  know  what  to  jump 
for.  The  fall  of  the  shutter  makes  a  spark  on  the 
time-line  (Fig.  4)  and  shows  the  meat;  the  dog  at- 
tempts to  jump  and  puUs  the  key,  making  another  spark. 
The  simple  reaction-time  is  thus  measured.  Pieces 
of  meat  are  then  put  behind  both  shutters,  the  dog's 
attention  is  attracted  to  a  spot  between  them,  one  shut- 
ter falls  and  he  jumps  toward  it  after  having  discrim- 
inated and  chosen. 

In  the  New  Haven  experiments  the  school  children 
were  required  to  distinguish  between  two  colours,  re- 
acting to  blue  and  not  to  red.  This  involved  the 
mental  processes  of  discrimination  and  choice,  in  addi- 
tion to  simple  reaction.  The  results  are  shown  in 
Fig.  80.  The  figures  at  the  bottom  indicate  the  ages, 
those  at  the  left  give  the  number  of  hundredths  of  a 
second  required  for  reaction  with  discrimination  and 
choice. 


48  Thinking,  Feeling,  Doing 


The  time  required  decreases  with  age.  On  the 
whole,  the  boys  and  girls  are  equally  quick,  the  differ- 
ences generally  being  too  small  to  be  worth  noticing. 
It  might  be  suggested  that,  since  boys  are  quicker  in 
simple  reaction,  they  must  take  a  longer  time  for  mere 
discrimination  and  choice  in  order  to  give  equal  totals. 
The  figures  seem  to  indicate  that  for  the  more  in- 
volved mental  pro- 


tucnoH 

Wrm  DISCRIMINATION 
AND  CHOICE. 


aOC  AKC  C1KL5 

JOrs 

CJSli 


cesses  the  girls  are 
quicker.  It  has 
been  suggested  that 
the  difference  may 
arise  from  the  fact 
that  games  of  boys 
generally  involve 
simple  activities 
that  must  be  rapid- 
ly performed,  while 
those  of  girls  are 
quieter  and  more 
intellectual. 

Every  thought  we 
think,  every  act  we 
perform,  takes  time.  Time  is  money.  Rapid  thought 
and  quick  action  sometimes  makes  all  the  difference 
between  success  and  failure.  A  man  who  can  think 
and  act  in  one  half  the  time  that  another  man  can, 
will  accumulate  mental  or  material  capital  twice  as 
fast.  If  we  could  think  twice  as  fast  as  we  do,  we 
would  live  twice  as  long,  although  we  would  live  only 
the  same  number  of  years.  Country  people  think  more 
slowly  than  city  people  ;  the  uneducated  are  slower 


Fig.  30.— Time  of  Thougrht  at  Various  Ages  in 
School  Children. 


Thinking-Time  49 

than  the  educated.  To-day  the  mental  processes  of 
the  mass  of  the  people  go  at  a  much  more  rapid  rate 
than  they  did  a  few  centuries  ago.  The  mind  has 
been  educated  by  our  whole  civilisation  to  act  more 
rapidly.  The  difference  between  the  sluggish  English- 
man of  mediaeval  times  and  the  quick  Yankee  of  to- 
day is  delightfully  told  in  Mark  Twain's  A  Yankee  at 
the  Court  of  King  Arthur.  If  it  were  possible  to  take  a 
man  of  two  centuries  as^o  and    brinor   liim    i^^to  the 

o  o 

laboratory,  the  results  obtained  from  experiments  upon 
him  would  be  entirely  different  from  those  obtained 
from  one  of  the  students  of  to-day.  The  reactions  of 
the  student  would  be  more  rapid,  especially  the 
complicated  ones. 

A  great  factor  in  the  education  of  children  is  to 
reduce  their  reaction-times.  When  the  country  boy 
lirst  comes  into  the  schoolroom  everything  he  does 
takes  him  a  very  much  .longer  time  than  when  he  has 
been  there  for  a  while,  especially  any  complicated  act 
Arithmetic,  for  example,  is  simply  a  matter  of  the 
association  of  a  set  of  ideas.  Let  the  teacher  give 
just  so  much  time  to  do  an  example.  When  that 
time  is  over,  the  pencil  must  be  put  down,  the  slate 
dropped.  The  child  is  thus  trained  to  think  and  act 
quickly. 

The  manner  in  which  rapidity  of  thought  is  increased 
by  practice  in  learning  a  language  has  been  made 
tbe  subject  of  experiment.  Ten  boys  were  taken  from 
each  class  of  a  high  school  and  were  asked  to  read 
rapidly  the  lirst  liundred  words  of  a  Latin  book.  The 
number  of  seconds  that  they  required  is  shown  in  the 
followmg  list  : 


50  Thinking,  Feeling,  Doing 

Class  10,  average  age     9,  average  time  262^ 


it 

9, 

11, 

135 

(( 

8, 

12, 

100 

(( 

7, 

13, 

89 

1( 

(3, 

14, 

79 

n 

5, 

15, 

57 

(( 

4, 

16, 

54 

u 

3, 

18, 

49 

(( 

2, 

19, 

48 

a 

1, 

22, 

43 

The  lowest  class  knew  notbinor  about  Latin,  the  rest 
had  beoun  it  in  Class  9. 

o 

When  the  same  children  were  tested  with  their 
native  language  tlie  results  were  successively  72,  55, 
43,  37,  39,  28,  27,  26,  25,  23^  There  was  a  similar 
gain. 

Was  the  gain  due  to  general  gain  in  mental  rapid- 
ity? One  hundred  papers  of  five  familiar  colours  were 
shown  and  each  child  was  required  to  name  them. 
The  average  times  were  83,  66,  79,  66,  63,  56,  63, 
63,  54^  There  had  been  a  general  gain  in  quickness 
but  not  nearly  so  great  a  gain  as  for  tlie  words.  A 
study  of  the  blunders  made  by  the  children  showed 
that  in  the  next  to  the  lowest  class  there  was  a  very 
slight  tendency  to  grasp  the  Latin  letters  as  words ; 
they  blundered  occasionally  by  reading  a  similar  word 
for  the  correct  one.  In  the  succeeding  and  higher 
classes  this  mistaking  of  words  became  steadily  more 
frequent ;  they  had  been  trained  to  grasp  larger  groups 
as  single  things  and  in  this  manner  to  save  time  in 
discrimination. 

How  far  we  can  push  the  education  of  rapidity  in 
all  the  elements  that  make  up  thinking-time,  reaction- 


Thinking-Time  51 

time,  and  action-time  can  be  seen  in  the  records  for 
rapidity  in  telegraphing  and  typewriting. 

By  careful  estimate  it  has  been  found  that  in  general 
press  matter  the  average  number  of  letters  per  word  is 
five,  and  that  the  average  number  of  vibrations  of  the 
key.  in  the  formation  of  the  telegraphic  characters  is 
five  to  each  letter.  Thus  on  the  average  there  are 
twenty-five  vibrations  of  the  key  in  the  formation  of 
each  word.  Now,  were  it  possible  for  an  operator  to 
transmit  sixty  words  per  minute,  he  would  make  one 
word,  or  five  letters,  per  second,  being  twenty-five 
vibrations  of  the  key  per  second. 

When  we  consider  that  the  telegraphic  alphabet  is 
made  up  of  dots  and  dashes  and  spaces  of  various 
lengths,  and  that  these  almost  incredibly  rapid  vibra- 
tions must  be  so  clear  and  clean  cut  as  to  be  easily 
read  by  the  ear,  we  can  form  an  approximate  idea  of 
the  wonder  of  such  an  achievement.  The  most  rapid 
manipulator  in  the  country  has  reached  a  speed  of 
fifty-four  words  per  minute,  which  is  about  23 J  vibra- 
tions of  the  key  per  second. 

In  using  the  typewriter  a  rate  of  about  120  words 
per  minute  has  been  attained  in  recording  an  address 
during  its  delivery.  In  writing  a  familiar  sentence 
repeatedly  a  speed  of  208  words  per  minute  has  been 
reached  ;  in  such  a  test  much  of  the  association  becomes 
somewhat  automatic. 


CHAPTER  Y 


RHYTHMIC   ACTION 


Fig.  31. — Tlie  Pneumatic 
Shoe. 


BY  rhythmic  action  we  understand  an  act  repeated 
at  intervals  which  the  doer  believes  to  be  regu- 
lar. Walking  is  a  simple  rhj^thm.  The  beating  of  a 
dram  is  intended  to  be  in  a  more  or  less  complicated 
rhythm. 

In  a  research  on  walking  the 
person  experimented  on  puts  on 
a  pair  of  shoes  with  hollow  rub- 
ber soles  (Fig,  31).  Each  sole 
communicates  by  a  long  tube 
with  a  small  capsule  that  writes 
on  a  small  smoked  drum  (Fig. 
32)  carried  in  the  hand.  When  the  foot  is  on  the 
ground,  the  air  is  pressed  through  the  tube  to  the  re- 
cording capsule  ;  this  causes  it  to  make  a  mark  on  the 
drum. 

The  character  of  the  results  is  indicated  in  Fig.  33. 
The  length  of  time  durino;  which  the  foot  rests  on  the 
ground  is  indicated  by  the  length  of  the  mark  on  the 
drum.  In  walking,  one  foot  leaves  the  ground  just  as 
the  other  touches  it;  in  going  upstairs,  both  feet  touch 
for  a  while  at  the  same  time;  in  running,  both  feet 
are  off  the  ground  for  short  intervals. 

52 


Rhythmic  Action 


53 


For  a  study  of  rhythm  as  it  appears  in  walking  I 
have  devised  a  little  reaction-key  for  the  foot,  to  be 
used  with  the  spark  method. 
This  key  is  shown  in  Fig.  8^. 
It  is  attached  to  the  heel  of  the 
shoe;  flexible  conducting  cords 
lead  from  it  to  the  spark-coiL 
The  spark-coil  is  arranged  to 
record  on  the  drum  by  making 
a  dot  on  the  smoked  paper  (p.  15). 


Fio.  8:{.  Graphic  Records:  1,  Walking; 
'4,  Going  Upstairs  ;  3,  Running  ;  4,  Faster 
Running. 


Fig.  32.— Walking  with 

Pneumatic  Shoes  and 

Recording  Drum. 


In  one  form  of  rhythmic 
action  which  I  may  term 
"regulated  rhythmic  ac- 
tion," a  person  attempts 
to  keep  time  with  a  regu- 
lar sound  of  some  kind, 
for  example,  a  regular 
click.  An  experiment  can 
be  arranged  in  the  follow- 
ing way:  To  produce  the 
click  we  use  the  graphic 
chronometer.      This  is  es- 

FiG.  34.-The  Electric  Shoe.  sCUtially      a       Stop  -  Watch 

which   makes  a  fine  pointer  beat  either  in  seconds 
or  in  fiftlis  of  a  secon<l.     This  pointer  writes  on  the 


54  Thinking,  Feeling,  Doing 

smoked  drum.  At  the  same  time  it  breaks  an 
electric  current  and  makes  a  click  by  means  of  a  tele- 
graph sounder. 

The  foot  key  is  fastened  to  the  heel  of  one  shoe. 
The  record  on  the  drum  will  be  like  that  shown  in 
Fig.  35.     It  shows  a  line  drawn  by  the  chronometer 


I    1,1.    I,    I,  I,    I,    I.   I.   I. 

Fig.  35.— Regular  Retarded  Rhythm. 

point,  on  which,  at  regular  intervals  representing  sec- 
onds, there  are  side  lines  corresponding  to  the  clicks. 
The  dots  are  made  by  sparks  at  the  moment  the  heel 
touches  the  floor. 

In  the  record,  shown  in  Fig.  35,  the  foot  struck  the 
floor  with  fair  regularity  about  two-tenths  of  a  second 
behind  time.  Another  person  of  nervous  temperament, 
or  the  same  person  anxious  to  do  better  but  flurried 
by  the  effort,  might  give  a  record  like  that  of  Fig.  36. 
On  an  average  the  step  is  still  behind  time  but  the 
beat  is  very  irregular.  Still  another  characteristic 
record  is  shown  in  Fig.  37.  The  step  is  very  regular 
but  slightly  ahead  of  the  click.  The  record  may. even 
show  on  an  average  neither  retardation  nor  accelera- 
tion, but  may  yet  be  irregular,  as  indicated  in  Fig.  38. 
The  ideal  of  precise  rhythmic  action  is  that  indicated  in 
Fig.  39  where  there  is  a  minimum  of  irregularity  and 
no  retardation  or  acceleration. 

The  distance  between  each  two  of  the  checks  in  the 
preceding  figures  means  an  interval  of  one  second. 


Rhythmic  Action  55 

With  a  fine  measure,  or  even  by  the  eye  alone,  we  can 
divide   the    interval    into  ten    parts,   each  of    which 

I    I     I,    '■','''    » 

Fig.  36.— Irregular  Retarded  Rhythm. 


i     }      1      t      I      t     t      I      f     .1 

Fig.  37.— Regular  Accelerated  Rhythm. 

f.     ,\     .1      I.     I.     1     J     .1      I.     t 

Fig.  38.— Irregular  Accurate  Rhythm. 

M    r   .1    I    I    t.    1   .1    1 

Fig.  30.— Regular  Accurate  Rhythm. 

will  mean  one-tenth  of  a  second.  Now,  note  down 
how  many  tentlis  of  a  second  tlie  dot  is  distant  from 
the  check ;  if  it  is  ahead  of  the  check,  ]^ut  +  in  front 
of  it;  if  behind,  — .  The  record  in  Fig.  36,  for  ex- 
ample, will  give 

-3,-4,-2,+  1,-1,-3,-1,  +  1,  +  2,  0. 

Take  the  average,  that  is,  add  them  all  up  and  divide 
by  ten.  This  gives  —  1.0  tenth  of  a  ^second  as  the 
average  amount  by  which  the  foot  was  behind 
time.  In  physics  this  is  called  the  constant  error;  in 
psychology — especially  in  educational  psychology — I 
propose  to  call  it  the  "index  of  inaccuracy." 

Now  let  us  find  the  "index  of  irreo^ularitv,"  or,  as  it 
has  already  (  p.  30)  been  called,  the  average  variation. 


56  Thinking,  Feeling,  Doing 

Find  llie  difference  between  the  number  in  the  index 
of  inaccuracy,  in  this  case  1,  and  each  of  the  numbers, 
3,  4,  2,  1,  etc.,  of  the  original  records.  You  will  get  a 
second  set  of  ten  figures,  2,  3,  1,  0,  0,  2,  0,  0,  1,  1.  As 
you  will  notice,  no  attention  has  been  paid  to  +  and  — . 
Average  these  last  results ;  answer,  1^,  or  1.0,  of  a 
tenth  of  a  second,  which  is  the  index  of  irregularity. 
By  chance  the  two  indexes  have  the  same  figures. 

A  very  irregular  person  might  have  the  same  index 
of  accuracy  as  a  very  regular  one  ;  they  might  both  be 
one-tenth  behind  time;  but  their  indexes  of  irregu- 
larity would  be  different.  On 
the  other  hand,  two  regular 
persons  will  have  small  indexes 
of  irregularity,  whereas  tlieir 
constant  errors  might  be  quite 
different. 

In  "  free  rhythmic  action  " 
the  person  makes  the  move- 
ment of  his  own  accord  and  is 
not  controlled  by  any  outside 
impulse.  Such  is  the  case  in 
walking,  in  marching  without 
FiG.40.— The  Electric  Baton,  anything  to  mark  time,  in  beat- 
ing time,  etc.  There  is  no  index  of  inaccuracy  because 
the  person  sets  his  own  time  ;  the  index  of  irregularity 
is  the  important  factor. 

To  measure  the  irregularity  in  a  case  of  an  orchestra 
leader,  for  example,  an  electric  contact  on  the  end  of 
a  baton  can  be  arranged  so  that  a  spark  record  is 
made  in   the  usual  way  (Figs.  40,    41).  Suppose 

we     have     a     record     of     eleven     beats     measured 


Rhythmic  Action 


57 


to  hundredths  of  a  second  with  the  following  results: 
41,  42,  87,  41,  89,  40,  40,  40,  41,  38,  41.  The 
averao-e  time  of  a    beat  is   just  40.     How  regular  is 


Fig.  41.— Taking  an  Orchestra  Leader's  Record  with  the  Electric  Baton. 

the  beating?  This  is  determined  by  finding  the  dif- 
ference between  each  separate  beat  and  the  average, 
and  takinof  the  averao;e  of  these  differences,  as  before : 
the  average  variation  here  is  1.1^. 

Now  let  us  take  another  orchestra  leader  whose 
record  gives  40,  41,  42,  40,  89,  87,  85,  40,  41,  41,  88 ; 
which  is  the  better  man?  The  average  is  40  as  before, 
but  the  index  of  irregularity  is  1.8  as  compared  with  1.1. 


58  Thinking,  Feeling,  Doing 

Suppose  we  have  a  third  leader  from  whom  we  get 
the  ten  records:  40,  39,  40,  40,  39,  38,  39,  39,  39, 
39.  The  average  is  39.2,  and  the  index  of  irregularity 
is  less  than  0.5. 

It  is  evident  that  the  second  leader  beats  so  irregu- 
larly that  an  orchestra  cannot  possibly  keep  time,  that 
the  first  leader  is  somewhat  better,  and  that  the  third 
is  far  superior  to  the  others.  The  actual  average 
time  of  a  beat  makes  no  difference  within  such  small 
limits,  as  music  played  at  the  rate  of  one  beat  in  0.40 
of  a  second  is  not  sensibly  different  from  tliat  played  at 
one  beat  in  0.39  of  a  second.  An  essential  qualification, 
however,  for  the  success  of  an  orchestra  leader  is  his 
regularity  in  estimating  intervals  of  time. 

Another  example  similar  to  the  one  just  mentioned 
is  that  of  a  piano  player,  who  must  learn  to  strike 
the  notes  at  regular  intervals.  The  quarter-notes 
should  all  be  about  the  same  length  ;  equal  measures 
should  be  completed  in  equal  times.  For  most  be- 
ginners the  irregularity  in  the  time  given  to  successive 
measures  varies  to  such  an  extent  that  it  is  painful  to 
hear  them  attempt  a  tune.  By  practice  with  the  me- 
tronome successful  players  are  able  to  reduce  their 
irregularity  till  it  does  not  disturb  the  playing.  It  is 
not  known  just  how  far  this  may  be  carried,  as  no  one 
has  ever  taken  the  trouble  to  make  measurements.  It 
might  be  suggested,  however,  that,  even  when  the  ir- 
regularity is  so  small  that  no  one  notices  it,  yet  it 
may  be  great  enough  to  injure  the  effect.  A  suc- 
cessful musician  of  any  kind  should  know  not  only 
that  his  instrument  is  in  tune  but  also  that  he  himself 
is  in  time. 


Rhythmic  Action 


59 


What  is  rhytlimic  action?  The  process  in  the 
mind  of  the  one  who  is  acting  is  in  the  first 
place  an  estimate  of  equal  intervals  of  time;  after 
a  few  strokes  at  equal  intervals  he  knows  just  when 
to  expect  the  next  one.  In  other  words,  it  is  a  case 
of  time-memory  corrected  by  an  actual  stroke  each 
time.  Knowing  when  to  expect  the  next  stroke, 
an  act  of  will  is  executed  so  that  the  movement 
occurs  in  some  definite  relation  to  the  stroke,  gen- 
erally at  the  same  moment  or  just  after  it.  This 
process  might  be  called  a  reaction  to  an  expectation. 


1 1  I  1 1 1  1 1  n  I  1 1 1  ■  I  '■■■""  I  I  I  I  I  I  I  I  I  ''  I  I  I  '"""  I  '"'"""  " 


Fig.  42.— Record  of  Arhythmic  Action. 

For  some  unexplained  reason  the  human  race  finds 
pleasure  in  rhythmic  action  as  seen  specially  in 
marching  and  the  dance.  That  this  desire  for  rhyth- 
mic action  has  its  source  deep  in  the  economy  of 
the  organism  can  be  seen  in  attempts  to  act  with- 
out rhythm.  Fig.  42  shows  a  record  of  movements  of 
the  fino-er  intended  carefullv  to  b>e  at  irregular  inter- 
vals  (the  record  was  obtained  by  the  method  of  air 
transmission  to  be  described  in  Chap.  VI).  We  see  at 
once  that  the  movements  repeatedly  come  in  regular 


6o  Thinking,  Feeling,  Doing 

gi'oups,  sometimes  witli  one  interval,  sometimes  witli 
anotlier.  At  tlie  start  tlie  in-egularity  is  somewhat 
suceessful,  but  with  fatigue  the  tendency  to  rliythmic 
action  becomes  marked.  Arhythmical  action  is  both 
difficult  and  displeasing;  our  pleasure  in  rhythm  may 
well  be  termed  an  "  organic  delight.  " 


CHAPTER  YI 

STEADINESS 

STEADIXESS  of  action  may  be  steadiness  of  position 
or  steadiness  of  movement.  In  position  the  im- 
pulses  to  the  various  muscles  are  so  arranged  that 
the  member  or  the  body  remains  still.  In  movement 
the  impulses  are  varied  in  power  in  such  a  way  that 
a  chano-e  occurs. 

In  studying  action,   voluntary  or  involuntar}',   we 


Fig.  4^5. —Arrangement  of  Capsules  for  Recording  Steadiness. 

need  to  have  some  method  of  recording  every 
part  of  the  act.  This  is  found  in  the  principle  of  air 
transmission. 

In  investigations  of  the  steadiness  of  position  we 
generally  make  use  of  a  pair  of  capsules  (Fig.  43). 
Each  consists  of  a  little  metal  cup  covered  with  thin 
rubber.  From  one  cup  a  tube  leads  to  the  other.  A 
very  light  lever  is  placed  above  each  cup;  the  lever 
is  connected  with  the  rubber  top.  If  one  of  the  levers 
is  moved  downward,  the  rubber  will  be  pressed  in  and 

6i 


62  Thinking,  Feeling,  Doing 

the  air  will  be  sliglitly  pressed  out  throiigli  the  tube. 
The  pressure  will  pass  along  the  tube  to  the  other  cap- 
sule, where  it  will  bulge  the  rubber  top  and  will  make 
tlie  other  lever  move  upward.  When  the  lever  is  re- 
leased, the  spring  will  draw  it  back,  the  air  will  be 
drawn  in,  and  the  other  lever  will  move  downward. 

To  make  a  record,  a  fine  metal  point  is  attached  to 
the  second  lever  and  this  is  made  to  write  on  a  metal 
cylinder  covered  with  paper  and  smoked  in  a  gas  flame, 
as  previously  described  (p.  14).     The  most  frequently 


Fig.  44.— Taking  a  Record  of  Steadiness. 

used  cylinder  for  slow   movements   is  a   clock-work 
drum  of  the  kind  shown  in  Fig.  44. 

Fig.  44  show^  a  person  with  his  eyes  closed,  trying 
to  hold  his  arm  steady.  Every  shake  of  the  arm  is 
transmitted  to  the  recording  point  and  is  scratched  in 
the  smoke  on  the  drum.     A  specimen  record  is  given 


Steadiness 


63 


in  Fio:.  45.  Durino^  the  time  between  the  two  vertical 
strokes  the  attention  was  disturbed  by  some  one  walk- 
ing around  the  room ;  steadiness  was  improved  by  dis- 
traction of  attention  (compare  with  page  17).  In  Fig. 
43  a  card  with  a  dot  is  placed  behind  the  lever  on 


Fig.  45.— a  Record  of  Steadiness. 


which  the  finger  is  to  rest ;  the  person,  with  eyes  open, 
tries  to  keep  the  end  of  the  lever  opposite  the  dot. 

Let   us  study  steadiness  in  a  special  case,  say  in 
holding   a   gun.     The   sportsman   takes  his  position, 


Fig.  4G.— Recording  a  Sportsman's  Unsteadiness. 

standing,   with  gun  aimed  at  the  target     A  thread 
hangs  down  from  the  gun  with  a  small  sinker  at  the 


64  Thinking,  Feeling,  Doing 


end  to  keep  it  stretched.  The  thread  is  given  one 
turn  around  the  lever  of  a  receiving  capsule,  as  seen 
in  the  figure.  The  weight  of  the  gun  makes  the  trem- 
blins:  slower  but  more  marked.  Fatio^ue  shows  itself 
quickly  in  large  movements.  By  an  extra  effort  of 
the  will  the  trembling  can  be  lessened  for  a  time  (com- 
pare p.  23). 

Can  steadiness  be  increased  by  practice?  Tliis 
problem  has  been  answered  in  respect  to  tlie  hand. 
The  arran2:ement  for  measurino;  steadiness  is  made 
very  sim[)le,  involving  no  capsules  or  drums.  It  con- 
sists of  a  flat  block  of  hard  rubber  supported  vertically 
by  a  rod.  On  tlie  face  of  the  block  is  a  strip  of  brass 
in  which  there  are  five  hard  rubber  circles,  l™"",  2""", 
3""",  4'"'",  and  S'"""  in  diameter.  The  edges  of  the  cir- 
cles are  flush  with  the  brass.  The  object  is  to  touch 
the  rubber  circle  with  the  metal  point  at  the  end  of  a 
stick  by  a  single  steady  movement.  Sufficient  un- 
steadiness of  the 
hand  will  cause 
the  point  to  touch 
the  metal.  With 
the  same  circle 
the  steadiness  of 
the  hand  can  be 
considered  to   be 

Fig.  47. -steadiness-gauge.  dirCCtly        propor- 

tional  to  the  percentage  of  successful  trials.  To  indi- 
cate when  the  metal  point  strikes  the  plate  instead  of 
the  circle,  an  electric  current  can  be  sent  from  one 
pole  of  a  battery  through  an  electric  bell  to  a  binding, 
post  connected  with  the  metal  plate,  and  from  the 


Steadiness 


65 


other  pole  through  a  flexible  conductor  to  the  metal 
point.  Any  contact  of  the  point  with  the  plate  will 
cause  the  bell  to  ring. 

In  making  the  experiment  the  plate  is  set  up  in 
front  of  the  person  experimented  upon.  The  pointer 
is  grasped  in  the  middle  like  a  lead  pencil ;  the  forearm 
is  rested  on  a  cushion  at  the  eds^e  of  the  table  and 
the  trial  is  made  by  a  single  steady  movement  under 
guidance  of  the  eye  (Fig.  48). 

A  series  of  experiments  on  the  subject  of  steadiness 
gave  the  following  results:  The  first  set  consisted  of 
twenty  experiments  with  the  left  hand ;  the  result  was 
fifty  per  cent,  of  successful  trials.  Immediately  there- 
after twenty  experiments  were  made  with  the  right 


Fig.  48.— Measuring  Steadiness  and  Attention. 

hand,  with  the  result  of  sixty  per  cent,  of  successful 
trials.  On  the  following  day  and  on  each  successive 
day,  two  hundred  experiments  were  taken  with  the 
right  hand,  the  same  conditions  in  regard  to  time, 
bodily  condition,  and  position  in  making  the  experi- 
5 


66  Thinking,  Feeling,  Doing 


ments  being  maintained  as  far  as  possible.  The  per- 
centages of  successful  trials  ran  as  follows :  61,  64,  65, 
75,  74,  75,  82,  79,  78,  88.  The  increase  in  accuracy 
is  represented  in  the  curve  in  Fig.  49. 

On  the  tenth  day  the  left  hand  was  tested  with 
twenty  experiments  as  before,  with  seventy-five  per 
cent,  of  successful  trials,  thus  showing  an  increase  of 
twenty  per  cent,  without  practice  in  the  time  during 
which  the  right  hand  had  gained  as  shown  by  the  fig- 
ures above.  This  is  an  illustration  of  the  curious 
process  I  have  ventured  to  call  "  cross-education  "  (see 
also  p.  22  and  Chap.  VII). 

The  pitch  of  a  tone  sung  from  the  throat  depends  on 
the  tightness  with  which  the  vocal  cords  are  stretched 
by  the  muscles  of  the  larynx.     If  a  singer  can  keep 


Fig.  49.— Result  of  Educating  Attention  to  the  Arm. 

these  muscles  steady  in  position,  the  tone  remains  the 
same  ;  if  he  allows  them  to  change  ever  so  little  the 
tone  changes. 


Steadiness 


67 


A  method  for  studying  the  accuracy  of  singing  a 
tone  is  found  in  the  gas-capsule  and  mirror-tuning- 


FiG.  50.— Testing  Steadiness  in  Singing.     Tlie  Unison. 

fork.  The  gas-capsule  consists  of  a  little  box  (Fig.  50) 
divided  into  two  parts  by  a  thin  rubber  membrane.  A 
gas  pipe  leads  to  one  part  and  a  small  burner  is  at- 
tached. The  person  sings  into  the  other  part.  Every 
vibration  of  the  voice  shakes  the  membrane  and  makes 
the  little  flame  bob  up  and  down  too  rapidly  to  be 
seen.  The  flame  is  placed  in  front  of  a  tuning-fork 
having  a  little  mirror  on  one  end.  The  fork  is  set 
going  and  the  person  sings  the  same  tone.  A  flame 
with  a  single  point  appears  in  the  mirror. 

Any  inaccuracy  or  change  in  pitch  in  the  singing 
makes  the  picture  rotate  in  the  mirror.  If  it  rotates 
in  the  way  the  flame  points,  the  person  sings  too  low  : 
if  backwards,  then  too  high.  If  the  singer  is  only  a 
trifle  wn-ong,  the  rotation  is  slow;  a  poor  singer  makes 
the  picture  fly  around  at  all  sorts  of  speeds. 

The  apparatus  can  do  more  than  this.     When  the 


68  Thinking,  Feeling,  Doing 

unison  is  sung,  a  flame  witli  a  single  point  is  seen 
(Fig.  60.)  AVhen  the  octave  is  sung,  a  double-pointed 
flame  appears  (P^ig.  51).     F(M"  the  duodecime  we  get 


Fig.  51.— Sin?:ing  the 
Octave. 


Fi(-,.  .'')2.— Sinking  the 
Duodecime. 


Fin.  rvJ— Singing  the 
Fifth. 


three  ])oints  Fig.  52)  ;  for  the  double  octave,  four 
points.  These  points  sec  in  to  bo  upright,  but  for 
musical  intervals,  such  as  the  fifth,  the  pointed  flames 
are    twisted    to    fretlier.     For  the  fifth    we  see  three 


Fig.  54.— Singing  the  Fourth. 


Fig.  55.— Singing  the  Third. 


points  twisted  as  in  Fig.  53 ;  for  the  fourth  we  get 
Fig.  54 ;  for  the  third  Fig.  55. 

When  these  intervals  are  properly  sung  the  flames  ap- 
pear sharp  and  steady  ;  any  inaccuracy  causes  rotation. 
The  apparatus  thus  tells  directly  how  steadily  the 
singer  maintains  his  pitch. 


CHAPTER  YII 


POWER   AXD   AVILL 

WHEN  on  liis  return  home  Ulysses  desired  to 
punish  the  insolence  of  the  beggar,  Irus,  by 
inflicting  a  severe  blow,  3'et  feared  lest  the  well- 
known  power  of  his  arm  would  betray  him  if  he 
put  forth  his  whole  strength,  he  deliberated  on  the 
amount  of  force  to  be  employed : 

"  Whether  to  strike  him  lifeless  to  the  earth 
At  once,  or  fell  him  with  a  measured  blow," 

and.  decided  to  deal  one  which  would  only  fracture 
the  jaw.  This  was  evidently  a  very  fine  regulation  of 
the  amount  of  exertion. 

We  first  take  up  the  problem 
of  the  accuracy  with  wliich 
force  is  exerted,  and  use  the 
grip  bet\A^een  thumb  and  finger 
for  illustration.  The  force  can 
be  measured  by  the  dynamo- 
meter shown  in  Fig.  56.  The 
upright  rod  holds  a  spring  scale 
of  appropriate  strength ;  the 
finger  is  placed  in  the  hook  of 
the  scale.  A  projecting  arm 
holds  a  cork  against  which  the'^''-''-'P"°^-'^'"""^^"^^'^" 
thumb  is  placed.     When  the  grip  is  exerted,  the  hook 

69 


70  Thinking,  Feeling,  Doing 

is  pulled  toward  the  cork.  A  second  projecting  arm 
is  so  fixed  by  a  collar  that  when  it  projects  in  front, 
the  hook  of  the  scale  strikes  and  hinders  further  move- 
ment. The  movement  is  arranged  to  stop  at,  say, 
one  pound,  or  500  grams.  The  person  is  seated  with 
the  eyes  closed.  The  stop  is  swung  on  and  the  press- 
ure is  exerted  till  the  hook  strikes;  this  is  a  pressure 
of  600  grams.  The  finger  is  released,  the  stop  is 
turned  back,  and  the  experiment  is  repeated.  As  the 
person  finds  no  hindrance,  he  stops  when  he  thinks 
he  is  exerting  the  same  force  as  before.  The  actual 
position  of  the  pointer  is  read  off  and  the  error  is 
noted.  Suppose  he  stops  at  470^  ;  he  then  makes  an 
error  of  — 30«.  The  experiment  is  repeated  a  number 
of  times  under  the  same  conditions.  The  results  can 
be  used  like  those  for  reaction-time  to  get  a  picture  of 
the  person's  mental  characteristics. 

Suppose,  for  example,  a  person's  average  force  to  be 
473^,  when  he  tries  to  reproduce  a  force  of  500^, 
His  constant  error  is  —  27^.  This  is  his  "error  of  re- 
production." 

The  error  of  reproduction  varies  with  the  size  of 
the  force  exerted,  but  not  proportionately.  If  the 
error  is  20^  on  a  force  of  200-,  it  will  be  30^  on 
400^  40^  on  800^  and  46^  on  1600^.  As  the  force 
grows  larger,  the  actual  amount  of  the  error  increases  • 
the  proportion  of  the  error,  however,  is  not  increased 
or  even  the  same,  but  is  decreased ;  20^  is  a  much 
larger  part  of  200^  than  46^  of  1600^. 

A  method  of  making  similar  experiments  with  the 
arm  is  to  lift  cylindrical  weights  between  thumb  and 
linger.     The  weights  are  sorted  into  two  groups,  those 


Power  and  Will 


71 


that  appear  the  same  as  the  standard  used  and  those 
that  appear  different.     The  amount  of  difference  that 


EUSCLE  SENSE 


Fig,  57.— Decrease  of  Inaccuracy  of  Weight-judgments  in  School- 
children of  Successive  Ages. 

passes  unnoticed  gives  an  idea  of  the  accuracy  of  the 
judgment.  This  is  generally  said  to  be  a  judgaient 
by  the  "muscle  vSense."  The  experiments  on  the 
New  Haven  school-children  showed  a  steady  gain  in 
accuracy  (Fig.  57). 

We  now  measure  the  strongest  grip  we  can  make 
between  thumb  and  finger.  This  we  repeat  at  short  in- 
tervals. It  is  evident  that  from  the  results  we  can 
obtain  the  curves  of  practice  and  habit  and  various 
other  information  by  the  methods  illustrated  in  the 
chapter  on  reaction-time.^ 

In  a  Yoluntarv  act  there  are  manv  mental  factors 
involved.  The  will  impulse  is  known  to  us  directly  ; 
we  know  what  we  intend  to  do.  What  we  actually  do  is 
known  to  us  in  many  ways  :  e.  g.^  by  sensations  from  the 
joints,  muscles,  and  skin.     We  thus  have  at  each  in- 

'  For  an  account  of  the  work  with  the  dynamometer  and 
the  ergograph  see  my  :^ew  Psychology,  Ch.  XV,  London  and 
New  York,  1897. 


72  Thinking,  Feeling,  Doing 

stant  the  means  of  comparing  what  we  intend  with 
what  we  feel  that  we  accomplish. 

What  is  the  relation  between  the  force  of  will  and 
the  act  itself  ?    The  force  of  the  act  we  have  measured 
in  pounds  or  grams.     Will,  not  being  a  mechanical 
process,  cannot  be  measured  by  any  pliysical  force ;  it 
can  be  measured  only  in  terms  of  will.     Yet  the  fol- 
lowing experiment  shows  how  we  can  bring  the  two 
into  relation.     We  will  to  make  a  weak  voluntary  act, 
then  one  twice  as  strong,  then  one  three  times  as  strong, 
etc.     Our  efforts  of  will  were  of  the  relative  strengths 
1:2:3:  etc.     The  force  of  the  voluntary  acts  shows 
the  same  relations  only  occasionally.    Each  person  has 
his  own  relations  of  scale  between  force  of  will  and 
force  of  action,  and  these  relations  change  under  dif- 
ferent circumstances.     Although  we  shall  not  know 
the  laws  governing  the  relations  between  tlie  two  un- 
til further  investigations  are  made,  yet  we  can   say 
that  increased  force  in  the  act  indicates  increased  force 
of  will,  and  likewise  increased  accuracy  in  the  act 
indicates  increased  accuracy  in  the  will-impulse. 

Are  we  justified  in  believing  that  an  increase  in  the 
force  of  action  indicates  not  only  increased  muscular 
power  but  also  increased  will  power?  Several  facts 
seem  to  indicate  an  affirmative  answer. 

It  has  often  been  noticed  in  the  gymnasium  that  an 
act  will  grow  steadily  stronger  by  training,  although 
not  the  slightest  change  can  be  detected  in  the  mus- 
cles. Moreover,  the  principle  of  "cross-education" 
(pp.  22,  66)  applies  here  also.  In  one  set  of  experiments 
the  greatest  possible  effort  in  gripping  was  made 
on  the  first  day  with  the  left  hand  singly  and  then  with 


Power  and  Will  73 

tbe  right  hand  ten  times  each.  The  records  were:  for 
the  left,  15  pounds ;  for  the  right,  15  pounds.  There- 
after, the  right  hand  alone  was  practised  nearly  every 
day  for  eleven  days,  while  the  left  hand  was  not  used. 
The  right  hand  gained  steadily  day  by  day ;  on  the 
twelfth  day  it  recorded  a  grip  of  25  pounds.  The  left 
hand — which  had  not  been  used  in  the  meantime — 
recorded  on  the  same  day  a  grip  of  21  pounds.  Thus 
the  left  hand  had  gained  six  pounds,  or  more  than 
one- third,  by  practice  of  the  other  hand. 

Experiments  have  shown  also  that  the  greatest  pos- 
sible effort  depends  on  the  general  mental  condition. 
The  greatest  possible  effort  is  greater  on  the  average 
among  the  intelligent  Europeans  than  among  the 
Africans  or  Malays.  It  is  greater  for  intelligent  me- 
chanics than  for  common  labourers  who  work  exclu- 
sively, but  unintelligently,  with  the  hands.  Intellectual 
excitement  increases  the  power.  A  lecturer  actually 
becomes  a  stronger  man  as  he  steps  on  the  platform. 
A  schoolboy  hits  harder  when  his  rival  is  on  the  same 
playground. 

It  has  even  been  observed  that  the  power  exerted 
varies  according  to  what  we  hear,  feel,  or  see.  With 
the  thumb-and-finger-grip  the  greatest  pressure  that 
could  be  exerted  on  one  occasion  during  silence  was 
eight  pounds.  When  some  one  played  the  giant's 
motive  from  the  Rheingold  the  grip  showed  8^ 
pounds.  The  slumber  motive  from  the  Walkiire  re- 
duced the  power  to  7)4  pounds.  The  effect  of  mar- 
tial music  on  soldiers  is  well  known. 

Just  how  much  of  the  inspiriting  effect  of  music  is  due 
to  the  rhythm,  the  time,  the  melody,  and  the  harmony, 


74  Thinking,  Feeling,  Doing 


has  not  been  determined.  Plato  empliasises  the  influence 
of  the  proper  music  on  the  formation  of  character.  He 
goes  no  further  than  to  s[)ecify  tlie  general  scales  in 
whicli  music  should  be  written.  The  liigh  Ljdian  is 
plaintive,  the  Ionian  and  Lydian  are  soft  and  convivial, 
the  Dorian  is  the  music  of  courage,  and  tlie  Phrj^gian  of 
temperance.  Aristotle  agrees  in  general  but  considers 
the  Phrygian  music  as  exciting  and  orgiastic.  It  has 
long  been  supposed  that  the  difference  among  the  scales 
was  one  of  arrangement  of  the  intervals  within  the 
octave,  corresponding  to  the  major  and  the  minor,  but 
the  more  recent  opinion  is  that  the  difference  is  one 
of  pitch.  The  Lydian  is  a  tone  to  a  tone  and  a  half 
higher  than  the  Phrygian,  and  the  Dorian  is  a  tone 
below  the  Phrygian.  The  Dorian  is  neither  too 
high  nor  too  low,  and  expresses  a  manly  character. 
It  might  be  suggested  tliat  the  special  melodies   as- 


FiG.  58.— Dynaraograph. 

sociated  with  each  scale  may  have  had  much  to  do 
with  the  case.  Nevertheless  it  has  been  proven  that 
the  pitch  itself  has  an  effect  on  the  greatest  strength  of 
grip. 


Power  and  Will 


75 


In  order  to  indicate  the  pressure  continuously  the 
dvnarriometer  can  be  arranged  in  connection  with  the 
capsule  of  the  graphic  method  (p.  61).  One  such  ar- 
rangement is  shown  in  Fig.  58.  As  the  hand  squeezes 
the  dynamometer  the  pointer  on  the  drum  moves  to 
one  side.  Every  fluctuation  in  the  squeeze  is  shown, 
and  when  the  smoked  paper  is  taken  from  the  drum 
and  varnished  we  have  a  complete  record.  Such  a 
tracing  from  a  hysterical  person  squeezing  as  hard  as 
possible  is  shown  in  Fig.  59.  The  power  of 
squeeze    is   changed  by  various    disturbances.     The 


Fig.  59.— Record  of  Strongest  Grip  of  the  Hand  by  a  Hysterical  Person. 

sudden  jerks  in  the  line  of  Fig.  59  are  tlie  re- 
sults of  the  ringing  of  a  gong.  The  sudden  in- 
creases in  power  occur  each  time  when  the  gong  is 
struck. 

Successive  single  contractions  can  also  be  registered 


Fig.  60.— Record  of  Successive  Squeezes  during  Ringing  of  a  Gong 
and  during  Silence. 

on  the  drum.  Fig.  60  shows  the  successive  squeezes 
of  one  person  with  the  hand — first  while  a  gong  was 
being   sounded,  then   in   silence.     Ti  e  gongs  on  the 


76  Thinking,  Feeling,  Doing 


trolley-cars   cannot,  however,  be   recommended  as  a 

strengthening  tonic. 

The  colours  also  affect  the  squeeze  with  some 
})ersons,  especially  hysterical  people. 
The  strongest  hand-squeeze  in  the  case 
of  one  such  subject  is  shown  in  Fig.  61. 
This  suggests  a  new  principle  in  the 
selection  of  colours  for  the  house,  for 
uniforms,  etc. 

Tastes    and    smells   have   different 


Fig.  62.— Influence  of  Musk. 

effects.      Fig.  62  shows  the  effect  of 

musk,  which  was  smelled  just  as  the 

^  c^?ra7tfoi^Xae  ^^^t  squcczc  was  made.     Tobacco  has 

en°^cSouk'^/^'^i^  ^  stimulating  effect.     Joy  and  anger 

iro^range^z/l^^yei-  incrcasc  the  powder,  sorrow  and  fright 

low ;  r,  red ;  v,  vio-  jg^j^gase   it.     An   entertaining    novel 

is    a    will-stimulant ;     a    prosy    text-book    actually 

weakens  us. 


CHAPTER  VIII 


TOUCH 

HERE  is  a  row  of  ten  little  disks,  3°^  in  diameter, 
cut  from  elder  pith.  Each  is  suspended  by  a  fine 

cocoon-fibre  from  a  little  handle.    For  portability  the 

handles  are   stuck   in  holes  in   a   support  (Fig.   63). 

Now  place  your  hand  comfortably  on  the  table  and  close 

your  eyes.    Tell  me  when  and  where  you  feel  anything 

touch  your  hand. 

Without     letting 

3'ou  know  what  I 

am  doins:  I  take 

the    handle   with 

the  lightestweight 

and  let  the  weight 

softly  down  till  it 

rests  on  your 

hand  (Fig.    64). 

You  do  not  know 

that  I  have  done 

so,     and    you    ieelFiG.63.— Touch-weights  for  Finding  the  Threshold 

nothing.  Then  I  try  the  next  heavier,  and  so  on,  till 
you  feel  the  pressure.  The  little  disks  are  graded  in 
weight,  thus  1™^,  2^^^^,  etc.,  up  to  10"^^. 

Now,  if  ihe  fourth  weight  was  the  first  you  felt,  then 
4™^  was  the  least  noticeable  weight,  or  the  weight  just 

77 


yS  Thinking,  Feeling,  Doing 

on  the  "threshold  of  intensity."  This  fact  of  the 
threshold  is  one  that  we  shall  meet  everywhere  in  the 
study  of  mind. 

The  threshold  of  sensation  for  the  sense  of  pressure 
in  an  average  subject  was  2"^^  for  forehead,  temples, 
and  back  of  forearm  and  hand ;  3"^^  for  inner  side  of 
forearm ;  5™g  for  nose,  hip,  chin,   and  abdomen ;  5"^^ 

to  15"^s  on  inner  sur- 
face of  fingers ;  and 
1000™^  on  heel  and 
nails. 

Some  idea  of  the 
delicacy  for  distin- 
guishing differences 
in  pressure  can  be 
obtained  by  laying  a 
hair   on    a    plate    of 

Fig.  &4.— Findingc   the  Threshold  for  the         -,  -, 

Pahn  of  the  Haud.  glass     and     putting 

over  it  ten  to  fifteen  sheets  of  writing  })aper.  Tlie 
position  of  the  hair  can  easily  be  felt  by  passing  the 
finger  back  and  forth  over  the  surface. 

Touching  with  movement  gives  much  more  delicate 
judgments  than  mere  contact.  A  book-cover  feels 
much  rougher  when  the  finger  is  moved  over  it  than 
when  it  is  merely  touched. 

Something  very  peculiar  occurs  when  a  light  pres- 
sure is  varied  rapidly  in  intensity.  If  the  tip  of  a 
tuning-fork  in  motion  be  lightly  touched  to  the  skin, 
it  "tickles." 

The  tickling  need  not  be  a  true  wavy  pressure  ; 
that  is,  it  need  not  be  perfectly  regular.  If  any  ob- 
ject, such  as  a  feather  or  the  finger,  be  held  lightly 


Touch 


79 


against  the  face,  a  tickle  is  felt,  due  to  the  tremblino-. 

Tlie  tickling  thing  need  not  stay  at  one  spot,  but 
may  be  moved  along  continuously.  A  feather  drawn 
over  the  temples  makes  a  strong  tickle.  A  fly  walk- 
ing over  the  skin  produces  an  unbearable  tickle  in 
exactly  the  same  way.  Stories  of  the  Thirty  Years' 
War  relate  how  the  soldier-robbers  forced  the  peasant 
to  reveal  his  treasure  by  subjecting  him  to  unbearable 
tickling.  Salt  was  spread  on  his  soles  and  a  cow  was 
allowed  to  lick  the  salt. 

When  a  pressure  is  already  felt,  it  can  be  made 
stronger  or  weaker  to  a  certain  degree  before  the 
change  is  perceived. 


Fig.  65.— Findin<?  the  Least  Noticeable  Change  iu  Pressure. 

The  experiment  can  be  made  with  a  pair  of  beam- 
balances.    The  hand,  supported  by  a  block  or  cushion, 


So  Thinking,  Feeling-,  Doing 

is  placed  under  the  scale-pan  so  that  when  the  scale  is 
at  rest,  the  pan-holder  just  touches  tlie  skin  (Fig.  66). 
To  avoid  the  coldness  of  the  pan,  a  ])iece  of  cork  or 
leather  is  placed  between  the  hand  and  the  metal. 

The  subject  of  experiment  closes  his  eyes.  A  weight 
is  placed  in  the  pan  above  the  hand.  A  sensation  of 
pressure  is  felt.  Sand  is  quietly  poured  into  the  same 
pan  until  the  subject  feels  the  ])ressure  to  be  increas- 
ing. By  putting  weights  in  tlie  othci-  pan  the  amount 
of  increase  can  be  measured.  Now  start  with  the 
same  weight  as  before  and  pour  sand  into  the  opposite 
pan  until  the  subject  feels  the  pressure  to  be  lighter. 
The  amount  of  sand  that  has  been  added  represents 
the  least  noticeable  change,  or  the  threshold  of  change, 
in  the  pressure.  Thus,  if  tlie  weight  at  the  start  was 
50"  and  the  amount  of  sand  added  was  35^,  the  least 
noticeable  change  was  85^,  or  ||-  of  the  original 
pressure. 

Several  facts  will  be  noticed  by  those  who  perfoi-m 
this  experiment.  In  the  first  place,  the  least  noticeable 
change  depends  on  the  rate  at  which  the  change  is  made. 
Several  funnels  should  be  used,  with  the  ends  of  differ- 
ent sizes.  When  one  of  these  is  filled  with  sand,  the 
rate  at  which  the  sand  flows  out  depends  on  the  size  of 
the  opening;  some  funnels  will  allow  the  sand  to  flow 
rapidly,  others  slowly.  When  the  same  experiment 
is  repeated  with  different  rates  of  flow,  it  will  be  found 
that  the  slower  the  flow  the  greater  the  least  noticeable 
change.  With  a  very  slow  flow  the  weight  can  often 
be  increased  two  or  three  times  over  before  the  change 
is  noticed. 

No  one  has  ever  tried  to  see  if  a  great  pressare  can 


Touch  8 1 

be  applied  to  tlie  human  skin  without  its  being  noticed, 
provided  the  rate  be  extremely  slow.  A  frog  with  the 
spinal  cord  cut  off  from  tlie  brain  is  quite  sensitive  to 
a  touch ;  vet  when  a  pressure  is  applied  by  screwing  a 
rod  down  at  the  rate  of  0.03"^™  in  one  minute  his  foot 
can  be  crushed  in  5J  hours  without  a  sign  that  the 
pressure  was  felt  (compare  with  the  experiment  on  the 
frog  in  Chap.  IX). 

Tiie  next  point  to  be  remarked  is  that  the  least  notice- 
able change  depends  on  the  weight  from  which  tiie 
pressure  is  started.  Roughly  speaking,  if  for  a  weiglit 
of  50^  the  least  noticeable  change,  at  a  certain  rate,  is 
30^ .  or  60  per  cent,  then  the  least  noticeable  change, 
at  the  same  rate,  for  25^  will  be  15^ ,  or  60  per  cent, 
also.  These  two  classes  of  facts  can  be  summed 
up  in  one  general  law :  the  threshold  of  change  in- 
creases inversely  as  the  rate  of  change  but  propor- 
tionately as  the  starting  pressure. 

The  least  noticeable  difference  is  quite  another  mat- 
ter from  the  least  noticeable  change.  The  usual  method 
of  experiment  employs  a  series  of  weights  successively 
growing  slightly  heavier  or  lighter  from  the  standard. 

Suppose  we  start  with  a  weight  of  20^  as  a  standard, 
and  have  a  set  of  weights  increasing  or  decreasing  suc- 
cessively by  steps  of  1^.  The  standard  is  first  applied, 
say,  to  the  palm  of  the  hand — the  hand  being  at  rest  on 
a  cushion.  It  is  then  removed  and,  after  about  two  sec- 
onds, the  21^  weight  is  applied  for  an  instant.  The 
subject  tells  whether  he  feels  it  lighter,  heavier,  or  the 
same.  After  a  short  time  the  standard  is  again  used  ; 
then  the  22 ^  weight  is  applied.  This  is  continued  with 
23^  ,  24^,  etc.,  till  the  subject  has  several  times  in  suc- 

6 


82  Thinking,  Feeling,  Doing 

cession  felt  tlie  weights  to  be  heavier.  Tlie  first  weight 
of  the  unbroken  succession  of  lieavier  weights 
gives  the  least  noticeable  difference.  For  example, 
suppose  a  set  of  experiments  to  give  the  following  re- 
sults :  21  equal,  22  heavier,  23  lighter,  24  equal,  25 
heavier,  26  heavier,  27  heavier,  28  heavier.  Then  the 
threshold  would  beat  5^. 

In  a  similar  manner  the  threshold  of  difference  can 
be  found  with  successively  lighter  weights.  For  a  gen- 
eral threshold  the  average  of  the  two  can  be  taken.  For 
example,  if  the  threshold  for  20^  toward  lightness  is  4^ 
and  the  threshold  toward  heaviness  is  5^ ,  the  average 
threshold  is4J^.  When  different  weights  are  used  as 
standards,  it  quickly  becomes  apparent  that  the  thresh- 
old of  difference  does  not  remain  at  the  same  number 
of  grams.  For  a  standard  of  200^  the  difference  of 
5^  will  not  be  felt  at  all.  The  threshold  will  be  more 
nearly  20^ . 

The  results  of  such  a  series  of  experiments  in  lifting 
weights  are  given  in  the  following  table : 


s 

1      2      5     10 

20    50 

100 

200 

500 

1,000 

2,000 

4,000 

D 

0.2  0.3  0.6  0.9 

1.5  2.8 

6.4 

10.8 

25 

57 

80 

100 

D 

S 

i      1      i      i\ 

t\    tV 

1 
i^ 

tV 

^^0 

tV 

1 

■25 

1 

The  figures  in  S  give  the  different  standards,  those 
in  D  give  least  noticeable  differences  ;  those  in  -g-  tell 
the  relation  of  the  least  noticeable  difference  to  the 
standard.  Thus,  for  a  standard  of  1^  the  least  notice- 
able difference  is  0.2  ^ ,  or  |  =  20  per  cent.  For 
1,000    it  is  67^ ,  or  ^ig-  =  5.7  per  cent. 

It  is  evident  that  the  least  noticeable  difference  does 
not  remain  the  same,  but  increases  as  the  standard  in- 


Touch 


83 


creases.  The  famous  law  of  Weber  would  say  that  the 
least  noticeable  difference  increases  in  the  same  ratio  as 
the  standard ;  in  other  words,  that  the  least  noticeable 
difierence  is  always  a  certain  fraction  of  the  standard. 
Tliis  is  not  true  for  pressure,  as  is  seen  by  the  line  of 
fractions  for  -^ ;  according  to  Weber's  law  they  should 
all  be  the  same. 

This  law  of  proportionality  of  differences  is  recog- 
nised in  many  tax  laws.  For  example,  the  income  tax 
demands  that  each  person  shall  pay  an  amount  in  direct 
proportion  to  his  income.  The  Mosaic  tithe  demanded 
a  tenth.  This  is  presumably  all  in  the  belief  that  a 
man  with  $100  feels  a  payment  of  $10  as  much  as  a  man 
with  $100,000  feels  one  of  $10,000. 

In  saving  that  like  differences  are  not  differences  of 
the  bame  amount,  but  are  differences  depending  on  the 
amount  from  which  you  reckon,  the  law  is  unquestion- 
ably true.  But  the  relation  of  pro- 
portionality is  much  too  simple  to 
meet  the  facts. 

It  is  a  curious  and  interesting  fact 
that  much  finer  differences  can  be  de- 
tected when  the  two  weights  are  ap- 
plied one  to  each  hand  at  the  same 
time. 

Let  us  now  find  the  "  threshold  of 
space"  for  the  skin.  An  ordinary 
})air  of  drawing  dividers  (Fig.  66)  can 
be  used,  but  accurate  work  requires  a  fig  cc-simpie^s- 

'  ^  tnesioineter 

better   apparatus.     The     compass    in 

Fig.  67  consists  of  a  horizontal  bar  on  which  the  two 

points  slide.     These  points  are  held  on  springs  so  that 


84  Thinking,  Feeling,  Doing 

the  experiments  can  be  made  at  a  constant  pressure. 

Place  the  two  points  at  I'""'  apart.  Take  the  aes- 
thesiometer  by  the  handle  and  gently  press  the  points 
against  the  forehead  of  some  one  who  has  his  eyes 
closed  and  who  has  not  seen  the  adjustment  of  the 
points.  He  is  to  say  whether  he  feels  two  points  or 
one.     At  this  distance  he  will  fee-1  only  one.     Adjust 

the  points  to  2'"'"  and 

try  again.      Proceed 

in   this   wav  till   he 

Ih ■  •  f^ r^-^V' •  •  "fTTTTfrii^"^ i^^HlM^rr^^ttiiiiTill  feels   the  two  points 

distinctly.  ISTow  start 

with     a     somewhat 

■c     r-    rr^    r^      w    x^  .1    ■      ^  OTcatcr  dlstancc  and 

Fig.  G(.— The  Complete  ^sthesiometer.        o 

proceed  backward  till 
only  one  pomt  is  felt.  The  average  of  the  two  results 
is  the  threshold  of  skin-space  at  the  particular  pressure 
for  the  particular  place  of  the  particular  person  ex- 
perimented upon. 

Here  is  a  specimen  table  of  results : 

Tongue 1""™ 

Inner  side  of  first  linger-joint  .     .     2' 

Lips  (red  portion) 6' 

Inner  side  of  second  finger-joint     .     7' 

Lips  (skin) 9' 

Cheek,  big  toe ll"'"^ 

Forehead 23'"'" 

Back  of  hand 81"''" 

Leg '.  40""" 

Neck 54"'"' 

Middle  of  back,  upper  arm,  thigh    68"'™ 

It  is  a  remarkable  fact  that  the  skin  can  be  educated 
by  practice  so  that  the  threshold  is  much  reduced. 

The  blind,  who  pay  constant  attention  to  their  finger- 


>mm 


'  mm 
1mm 


Touch 


85 


various 


tips,  have  very  small  thresholds.  Curiously  enough, 
their  thresliohls  are  also  smaller  on  the  back  and  on 
other  places  which  they  do  not  use  more  than  other 
people.  The  superiority  of  the  blind  in  that  respect 
would  seem  to  be  due  to  increased  attention  to  the  skin. 
A  further  evidence  of  this  explanation  is  the  fact  that 
education  of  one  part  of  the  body  brings  a  special 
decrease  of  the  threshold  for  the  neighbouring  parts 
and  for  the  same  portion  of  the  opposite  side  of  the 
body.  There  is  a  kind  of  transference  of  practice  that 
resembles  cross-education  (pp.  22,  66,  72). 

Our  experience  has  taught  us  that  the 
portions  of  the  skin  stand  in  certain 
space  relatione.  Thus  w^e  know  that 
somethino;  touchino;  the  middle  fimi^er 
is  further  from  the  thumb  than  some- 
thin  o^  toucl'inof  the  index  fimier. 
When  the  fingers  are  out  of  their 
places  we  are  irrestibly  driven  to 
judge  as  if  they  were  in  proper  order. 
This  is  illustrated  by  wliat  is  known 
as  Aristotle's  experiment.  The  mid- 
dle finger  is  crossed  over  tlie  index  ^^''''  ^uuitkm^^^^^'^ 
finger  in  such  a  way  as  to  bring  the  tip  of  the  middle 
finger  on  the  thumb-side  of  the  other.  A  pea  or  other 
small  object,  when  inserted  between  the  two,  will 
appear  as  two  objects.  It  is  difficult  to  re-learn  the 
arrangement  of  the  skin  in  space.  We  thus  see  why  a 
person  whose  nose  has  been  re-formed  by  a  piece  of 
skin  from  the  forehead,  for  a  while  feels  all  contact  on 
the  nose  as  if  it  were  contact  on  the  forehead. 

A  similar  illusion  is  produced  by  placing  a  pencil 


86  Thinking,  l^eeling,  Doing 

between  tlie  lips  and  moving  tlie  under-lip  to  one  side. 
There  are  apparently  two  pencils. 

The  distance  between  two  points  on  the  skin  seems 
greater  when  tlie  skin  between  these  points  is  also 
touched.  If  four  pins  are  pounded  in  a  straight  line 
into  a  stick  at  one-fourth  of  an  inch  apart,  the  distance 
between  the  end  pins  will  appear  greater  than  that 
between  two  separate  pins  three-fourths  of  an  inch 
apart. 

The  distances  apart  of  the  various  points  that  we 
feel  are  what  we  know  under  the  names  of  smoothness 
and  roughness.  A  billiard-ball  is  "smooth,"  that  is, 
our  sensations  of  touch  are  evenly  distributed.  Car- 
pet is  "rough,"  that  is,  it  produces  uneven  sensations. 
Sandpaper  is  peculiarly  "  rough,"  because  very  intense 
and  limited  sensations  from  the  sharp  sand  are  mingled 
with  smoother  ones  and  gaps.  Velvet,  when  felt  back- 
ward, has  a  peculiar  rough  smoothness,  because  the 
separate  points  of  the  individual  hairs  produce  sepa- 
rate sensations,  yet  are  so  near  together  as  to  resemble 
smoothness.      Shortnap  plush  has  a  similar  feeling. 


CHAPTER    IX 

HOT    AND    COLD 

IN  the  old  days  it  was  supposed  that  heat  and  cold 
were  two  different  things  ;  even  to-day  the  every- 
day person  cannot  grasp  the  idea  that  coldness  is 
simply  the  absence  of  heat,  that  a  piece  of  ice  is 
cold  simply  because  it  is  not  hot.  But  the  modern 
development  of  physics  has  shown  that  heat  consists 
of  motion  among  the  little  molecules  of  which  all 
bodies  are  su})posed  to  be  composed,  and  that  as  this 
motion  becomes  less  the  bodies  are  said  to  be  cold. 
Thus  a  glass  of  warm  water  differs  from  a  glass  of  cold 
water  simply  in  the  fact  that  the  molecules  of  the 
water  in  the  former  are  moving  rapidly,  while  in  the 
latte»'  they  are  comparatively  quiet. 

Strange  as  it  may  seem,  it  was  discovered  a  few 
years  ago  that  the  ordinary  common  sense  of  every- 
day people  was  right.  Not  that  the  science  of  physics 
was  wrong,  but  that  the  conclusion  drawn  was 
incorrect.  Hotness  and  coldness  are  two  entirely 
different  things  from,  our  point  of  view.  A  glass  of 
water  is  warm  because  it  gives  "US  a  feeling,  or  sensa- 
tion, of  warmth  ;  another  glass  is  cool  because  it  gives 
us  an  entirely  different  sensation  of  coldness.  The 
complete  distinction  of  our  feelings  of  hotness  and 
coldness  from  the  phj^sical  condition  of  the  molecules 

87 


88  Thinking,  Feeling,  Doing 

of  the  object  touched  is  emphasised  by  an  experiment 
in  whicli  the  same  object  feels  both  hot  and  cold  at 
the  same  time  (see  below). 

Our  sensations  of  hot  and  cold  come  from  little  spots 
called  hot  spots  and  cold  spots.    To  find  the  cold  spots 
a  pointed  rod,  e^.,  a  lathe  centre,  a  pointed  nail,  or 
even  a  lead  pencil,  is  cooled  and  then  moved  slowly 
and   lightly  over  the  skin.      At  certain 
•*:?••  'Vvi*    points  distinct  sensations  of  cold  will  flash 
Ai  '^  •  out  while  elsewhere  nothing  but  contact 
or  vague  coldness  is  felt.     These  points 
are  the  cold  spots ;  a  specimen  arrange- 
ment of  them  is  shown  in  Fig.  69. 

To  find  the  hot  spots  the  metal  point  is 
FxG.  69  -A  Cold-  warmed  and  applied  in  a  similar  manner. 

spot  Map.  ^  ^ 

The  hot  spots  are  everywhere  different 
from  the  cold  spots.   A  specimen  case  is  shown  in  Fig. 70. 

At  the  art  store  get  a  few  pounds  of  plaster  for 
casts  (the  finely  ground  plaster,  not  the  ordinary  plaster 
of  Paris).  Mix  it  with  water  in  a  bowl.  Pour  out  a 
portion  into  a  tin  pie-plate.  Now  press  the  hand  (palm 
or  back)  down  upon  it,  being  careful  to  touch  the  plaster 
at  every  point.  When  the  plaster  has  hardened  suffi- 
ciently to  permit  the  removal  of  the 
hand  without  sticking,  carefully  raise  it. 
A  perfect  cast  of  the  hand  is  obtained  S'*'*:^ 
with  every  line  expressed.  ..•*••.•  *>**  J 

Now  prepare  yourself  with  a  glass  of       *t/\*   ••'•»  * 
ice  water,  a  glass  of  hot  water,  some  red  j^ 

and   some   blue  ink,   a   pointed   metal    fig.  7o.-a  Hot-' 
pencil  (or  a  sharp  lead  pencil),  and  a        ^^°^    ^^' 
couple  of   tooth-picks.      Cool  the  pencil   in   the  ice 


Hot  and  Cold 


89 


water.  Dry  it  and  pass  it  over  the  skin.  Whenever  a 
cold  spot  flashes  out,  mark  its  position  in  blue  ink 
with  a  tooth-23ick  on  the  cast.  The  fine  creases  in  the 
skin  will  enable  you  to  locate  it  exactly.  Repeat  this 
a  few  times,  till  you  are  satisfied  that  you  have  a  map 
of  all  the  cold  spots.  Wai'in  the  pencil  in  the  hot 
wafer  and  find  the  hot  spots  in  the  same  way.  Mark 
them  on  the  cast  in  red  ink.  AVhen  you  have  fin- 
ished you  will  have  a  complete  geography  of  your 
temperature  spots  on  a  relief  map. 


Fig.  71.— Finding  the  Hot  and  Cold  Spots. 

The  hot  spots  are  ordinarily  not  sensitive  to  cold- 
ness or  the  cold  spots  to  heat.  Yet  a  very  hot  point 
applied  to  a  cold  spot  so  as  not  to  reach  hot  spots  also 
will  feel  cold ;  of  course,  to  a  hot  spot  it  is  intensely 


90  Thinking,  Feeling,  Doing 

hot.  It  is  noteworthy  that  when  the  hand  is  applied 
to  a  very  hot  or  a  very  cold  object  there  is  often  doubt 
for  a  few  moments  whether  it  is  hot  or  cold,  because 
both  sets  of  spots  are  stimulated. 

The  temperature  spots  answer  to  tapping  by  sensa- 
tions of  hot  or  cold.  For  an  experiment,  choose  a  sen- 
sitive cold  spot  and  let  some  one  tap  it  with  a  fine 
wooden  point-,  it  will  feel  cold.  Thrust  a  needle  into 
it;  it  will  feel  no  pain. 

In  stud^nng  the  subject  of  touch  we  had  occasion  to 
notice  a  certain  law  of  change  (page  79).  Does  such 
a  law  hold  good  for  hot  and  cold?  By  experiments 
with  a  special  apparatus  I  was  able  to  prove  tluit  it 
did;  the  smallest  noticeaV)le  change  depended  on  the 
rate  of  change.  But  complicated  apparatus  is  not 
necessary  to  illustrate  the  law ;  anybody  can  do  it  by 
means  of  a  lamp  and  a  spoon.  Let  some  one  else  hold 
the  spoon  by  the  extreme  end  ;  you  yourself  put  your 
finger  about  half  way  down  the  handle.  The  bowl 
of  tlie  spoon  is  now  held  over  a  lamp  so  that  it  will 
slowly  become  hot.  After  a  while  the  handle  of  the 
spoon  under  your  finger  begins  to  feel  slightly  warm. 
Lift  the  finger  and  immediately  place  the  same  finger 
of  the  other  hand  on  the  same  place.  The  spoon  will 
be  found  to  be  quite  warm  or  even  painfully  hot. 
When  the  heat  was  gradually  increased  it  was  scarcely 
noticed,  but  when  suddenly  increased,  it  was  clear 
at  once ;  in  short,  the  sensitiveness  to  heat  depends 
on  the  rate  of  change. 

Although  a  frog  jumps  readily  when  put  in  warm 
water,  yet  a  frog  can  be  boiled  without  a  movement, 
if  the  water  is  heated  slowly  enough.     In  one  experi- 


Hot  and  Cold 


91 


ment  (Fig.  72)  the  water  in  a  bowl  was  heated  by 
means  of  a  little  flaine  under  the  bulb  which  com- 
municated with  the  bowl  by  a 
tube ;  the  temperature  rose  at 
the  rate  of  0.002°  C  (to'oVo  of 
a  degree  Fahrenheit)  per  second 
as  indicated  by  a  thermometer 
in  the  bowl.  The  frog  never 
moved  and  at  the  end  of  two  and 
one  half  hours  was 
found  dead.  He 
had  evidently  been 
boiled  without  no- 
ticing it 

There  is   a  curi- ^    ^^^    ^  ...       ^        .^^    .„.  .^ 

Fig.  1 2. — Boiling  a  Frog  without  His  Knowing  it. 
OUS   connection    be-  No  sensation  with  an  Extremely  Slow 

tween  temi)erature  ^^'^  °^  ^^^'^^^• 

and  pressure.  Cold  or  hot  bodies  feel  heavier  than 
bodies  of  equal  weight  at  the  temperature  of  the  skin. 
For  cold,  take  two  silver  dollars ;  keep  one  of  them 
closed  in  the  hand  to  give  it  the  temperature  of  the 
skin,  but  cool  the  other.  Apply  them  in  succession 
to  the  palm  of  some  one's  hand.  The  cold  one  will 
seem  much  heavier.  Heat  does  not  make  so  much 
difference  as  cold.  For  a  careful  experiment  take  two 
wooden  cylinders  of  equal  weight  and  heat  one  very 
hot  in  an  oven.  Apply  the  cylinders  on  end  to  the 
back  of  the  hand.  This  phenomenon  illustrates  the 
fact  that  a  sensation  of  one  kind  often  causes  an  ap- 
parent increase  in  the  strength  of  another  sensation. 


CHAPTER  X 

SMELL   AND  TASTE 

IN  spite  of  the  antiquity  of  language,  we  have  no 
names  for  smells.  When  we  notice  an  odour,  we 
name  it  by  the  source  from  which  it  comes.  We  speak 
of  the  odour  of  violets,  of  new-mown  hay,  of  onions, 
and  so  on,  but  we  have  no  name  for  the  odour  itself. 
Such  a  lack  is  not  present  in  sight,  hearing,  or  even 
taste.  A¥e  might  say  that  certain  things  taste  like 
sugar,  certain  others  like  quinine,  and  so  on ;  but  that 
would  be  only  a  roundabout  way  of  saying  they 
were  "sweet"  or  "b.tter."  Instead  of  classifying 
the  colours,  as  grass  colour,  dandelion  colour,  coal 
colour,  etc.,  we  say  green,  yellow,  black,  etc.  But  in 
smell  we  can  only  speak  of  cabbage  odour,  fishy  odour, 
violet  odour,  and  the  like. 

Not  only  do  we  have  no  names  for  odours,  we  do 
not  know  any  reason  why  difi'erent  things  smell  alike. 
Why  should  compounds  of  arsenic  smell  like  garlic? 
If  we  mix  sulphuric  acid  with  water,  we  get  an 
odour  like  musk.  It  is  said  that  emeralds,  rubies, 
and  pearls,  if  ground  together  for  a  long  time,  give 
out  an  odour  like  that  of  violets.  Again,  ringworm 
of  the  scalp,  the  body  of  a  patient  sick  with  typhoid, 
and  a  mouse  have  similar  odours. 

92 


Smell  and  Taste  93 

Perfumes  can  often  be  placed  in  similar  groups.  The 
rose  type  includes  geranium,  eglantine,  and  violet- 
ebony  ;  the  jasmine  type,  lily  of  the  valley  and  ylang- 
ylang;  the  orange  type,  acacia,  syringa,  and  orange- 
flower;  the  vanilla  type,  balsam  of  Peru,  benzoin, 
storax,  tonka  bean  (usually  sold  for  vanilla  extract), 
and  heliotrope  ;  the  lavender  type,  thyme  and  mar- 
joram ;  the  mint  type,  peppermint,  balsam,  and  sage ; 
the  musk  type,  musk  and  amber  seed  ;  the  fruity  type, 
pear,  apple,  pine-apple,  and  quince. 

What  is  the  threshold  of  smell?  There  is  a  con- 
venient but  not  higlily  accurate  way  of  answering  the 
question  by  means  of  the  olfactometer,  or  smell 
measure. 

The  olfactometer  (Fig.  73)  includes  a  glass  tube  fas- 
tened on  a  narrow  board.   Inside  this  tube 
is  a  narrow  strip  of  blotting-paper  mois- 


I'^^n'^rrrrrTTT- 


3     4      5     e     T     8      9     10    II     12    13    14    IS    16    17    Id 


Fig.  73.— Olfactometer.  "^^ 

tened  with  the  object  to  be  smelled.  A  solution  of 
camphor  in  alcohol  is  convenient;  the  solution  dries, 
leaving  the  strip  filled  with  small  particles  of  cam- 
phor. Any  other  not  too  odorous  liquid  may  take 
the  place  of  the  camphor  solution.  Inside  the  tube 
is  a  smaller  one  on  the  end  of  which  is  a  piece  of 
rubber  tubing.  A  scale  is  marked  on  the  board  below 
the  tubes. 

The  end  of  the  smaller  tube  is  pushed  to  the  end  of 


94  Thinking,  Feeling,  Doing 

the  larger  one.  The  old  air  in  it  is  blown  out.  The 
rubber  tube  is  put  to  the  nose.  The  smaller  tube  is 
now  slowly  drawn  backward,  while  the  person  breathes 
air  in  through  it.  When  he  first  perceives  an  odour, 
the  distance  through  which  the  smaller  tube  has  been 
drawn  from  the  end  of  the  larger  one,  is  noted.  Now, 
the  further  the  tube  is  drawn  back,  the  greater  the 
distance  over  the  blotter  travelled  by  the  air  breathed  ; 
consequently  there  is  more  of  the  camphor  in  the 
air.  The  number  thus  noted  down  gives  an  idea, 
though  not  a  very  accurate  one,  of  the  person's 
threshold  of  smell. 

In  the  whole  range  of  psychology  there  is  nowhere 
to  be  found  a  more  striking  method  of  illustrating  the 
difference  between  the  different  thresholds  of  know- 
ledge. As  the  smelling-tube  is  pulled  backward  the 
observer  at  first  notices  no  odour ;  the  odour  is  said  to  be 
below  the  threshold.  After  a  while  he  says  :  "  I  smell 
something,  but  I  can't  tell  what  it  is";  a  sensation  is 
there,  it  is  known  as  an  odour,  it  has  passed  the  "thresh- 
old of  sensation,"  but  has  not  reached  the  "  threshold  of 
recognition"  (if  I  may  use  such  an  expression).  The 
odour  becomes  stronger  and  stronger ;  finally  the  ob- 
server exclaims,  "  Now  Iknow  the  odour ;  let  me  think 
a  moment  and  I  will  tell  you  the  name."  Very  fre- 
quently he  recognises  the  odour  without  being  able 
to  recollect  the  name.  The  difference  between  the 
threshold  of  sensation  and  the  threshold  of  recognition 
is  often  considerable.  If  the  odour  is  still  further 
increased,  the  name,  for  usual  substances,  is  readily 
recollected. 

Our  sense  of  smell  can  be  fatigued.   Holding  a  piece 


Smell  and  Taste 


95 


of  camphor  for  some  minutes  before  the  nose  will 
raise  the  threshold  for  camphor.  With  an  olfactometer 
cliarged  with  camphor  the  threshold  as  measured  before 
fatis^uinor  the  sense  of  smell  will  be  found  to  be  much 
lower  than  the  threshold  afterwards.  Sometimes  the 
fatigue  is  so  great  that  the  smell  of  the  camphor  is 
entirely  lost.  Strangely  enough  the  fatigue  affects 
some  odours  and  not  others.  If  the  sense  be  affected 
by  camphor-fatigue,  the  smell  of  wax  will  be  dimin- 
ished or  lost,  but  essence  of  cloves  will  appear  un- 
diminished in  strength. 

We  have  two  senses  of  smell,  namely,  the  two  halves 
of  the  nose.  When  two  different  smells  are  received^ 
one  from  each  organ,  we  are  driven  to  notice  first 
one,  then  the  other.  When  a  rose  is  placed  in  one 
|)aper  tube  (Fig.  74)  and  a  water-lily  in  another  and 
the  tubes  are  so  ar- 
ranged that  the  od- 
ours get  to  separate 
nostrils  without  mix- 
ing, we  do  not  smell 
a  combination,  but 
alternately  either 
rose  or  water  -  lily. 
We  can  smell  either 
one  in  preference  to 
the  other  by  simply  '^r^ 
thinking  about  it 
(compare  p.  21).  It 
is  a  very  curious  fact  that  we  are  unable  to  think  of 
the  same  odour  steadily  ;  our  thoughts  irresistibly  turn 
from  one  to  the  otlier  and  thus  the  smells  alternate. 


Fig.  74.  —Alternation  of  Odours  ;  or  the 
strife  of  the  Two  Nostrils. 


9^  Thinking,  Feeling,  Doing 

The  greater  attention  paid  to  sight  and  hearing  has 
apparently  caused  a  neglect  of  smell  and  a  consequent 
deterioration.  The  acuteness  of  smell  amongr  animals 
is  well  known.  Among  certain  persons  this  sense  also 
attains  great  development.  I  have  a  case — reported 
by  a  perfectly  competent  witness  who  lived  for  years 
with  the  person  mentioned — of  a  woman  in  charge  of  a 
boarding-school  who  always  sorted  the  boys'  linen 
after  the  wash,  by  the  odours  alone. 

For  the  tastes  we  are  much  better  oflf  than  for  the 
smells ;  we  have  names  for  them.  We  say  that  some- 
thing is  "sour,"  that  it  is  "sweet,"  etc.,  and  do  not 
need  to  name  the  taste  after  the  object. 

The  great  diversity  of  flavours  of  objects  is  due 
mainly  to  smell.  When  a  cold  in  the  head  injures 
the  ability  to  smell,  the  flavours  of  the  dinner- table 
disappear  for  the  most  part. 

Experiments  on  taste  without  smell  can  be  made  by 
filling  the  nose  cavity  with  water  while  the  head  is  in 
an  inverted  position ;  simply  holding  the  nose  without 
breathing  is  almost  as  good. 

When  the  sense  of  smell  is  entirely  lost,  the  ordinary 
flavouring  syrups  such  as  vanilla,  currant, orange,  straw- 
berr}^,  and  raspberry  give  merely  a  sweetish  taste  with 
no  distinction  among  them.  Lemon  syrup  tastes  sweet 
and  sour.  Candies  flavoured  in  this  way  taste  alike. 
Mustard  and  pepper  produce  sharp  sensations  on  the 
tongue ;  there  is  no  difi^erence  between  them  except 
that  pepper  is  sharper;  neither  produces  a  real  taste. 
Tea  does  not  differ  from  water  or  coffee,  Rhine  wine 
from  diluted  vine2:ar.  Gincfer  and  cloves  are  alike. 
Powdered  cinnamon,  when  placed  on  the  tongue  of  a 


Smell  and  Taste  97 

person  whose  eyes  are  closed  and  whose  nose  is  held 
between  the  fincrers,  is  considered  to  be  like  meal. 

Wines  owe  their  bouquet  entirely  to  smell.  The 
most  exquisite  Schloss  Johannisberger  does  not  differ 
from  diluted  vinegar  as  far  as  taste  goes.  Coffee  like- 
wise owes  its  flavour  to  smell.  Boiled  coffee  has  lost 
its  aroma  and  is  merely  a  combination  of  sour  and 
bitter.  Through  unpardonable  stupidity  pepper  is 
always  served  ground  and  consequently  odourless,  the 
little  German  pepper-mids  being  unknown  in  America. 

When  all  smells  and  touch  and  temperature  sensa- 
tions are  gotten  rid  of,  the  things  we  taste  can  be  sorted 
into  six  different  classes :  soar,  sweet,  salt,  bitter, 
metallic,  alkaline,  and  their  combinations.  Charac- 
teristic examples  of  these  are  found  in  lemon  juice, 
sugar,  salt,  quinine,  zinc,  and  washing  soda.  The  ele- 
mentary tastes  can  be  combined  in  countless  ways. 
Thus,  sweet  and  sour  when  combined  produce  a  result 
that  is  neitlier  sweet  nor  sour,  but  differs  from  either 
while  resembling  both.  Unfortunately  psychologists 
have  not  attempted  to  unravel  the  com]30und  tastes 
into  their  elements. 

Probably  no  more  convenient  or  striking  illustration 
of  the  threshold  can  be  presented  than  in  experiments 
on  taste. 

The  threshold  for  sweetness  can  be  found  by  using 
a  solution  of  sugar  of  known  strength.  An  ounce  of 
sugar  dissolved  in  twenty  ounces  of  water  makes  a  five 
per  cent,  solution.  For  simple  illustration  it  is  sufficient 
to  place  a  spoonful  of  sugar  in  a  small  wine-glass  of 
water.  Some  pure  drinking  water  and  two  medicine 
droppers  are  to  be  provided. 
7 


9^  Thinking,  Feeling,  Doing 

A  small  glass  is  used,  preferably  a  graduated  med- 
icine glass,  containing  one  ounce  of  pure  water.  With 
one  of  the  droppers  a  quantity  of  the  sugar  solution  is 
taken  up ;  one  drop  is  allowed  to  fall  into  the  water. 
The  water  is  then  stirred  with  the  otlier  dropper ;  a 
small  quantity  is  taken  up  in  it  and  one  drop  of  this 
homeopathic  solution  is  allowed  to  fall  on  the  tongue 
of  the  person  tested.  He  will  not  taste  anything,  owing 
to  the  extreme  dilution.  The  experiment  is  repeated, 
adding  one  drop  each  time,  till  a  taste  is  noticed.  The 
number  of  drops  used  will  indicate  the  threshold  of 
taste.  If  the  five  per  cent,  solution  and  a  graduated 
glass  have  been  used,  it  is  an  easy  matter  to  calculate 
just  how  strong  this  least  noticeable  taste  is. 

Similar  experiments  can  be  made  with  salt,  quinine, 
acid,  and  alkali.  The  most  convenient  solutions  to 
use  are  sugar,  5  per  cent. ;  quinine,  0.002  per  cent.  ;. 
tartaric  acid,  0.5  per  cent.  ;  salt,  2  per  cent.  ;  sodium 
carbonate,  0.1  per  cent. 

To  avoid  the  effect  of  suggestion  it  is  advisable  to 
have  more  than  one  solution  ready  and  not  to  let  the 
person  tested  know  which  is  being  used. 

How  far  the  education  of  the  sense  of  smell  can  be 
carried  is  shown  by  the  tea-tasters  who  can  tell  the 
locality  in  China  from  which  each  chest  of  tea  comes. 

Our  appreciation  of  a  taste  depends  on  its  quantity. 
A  single  drop  of  sugar  solution  on  the  tongue  does  not 
seem  so  sweet  as  a  mouthful. 

It  is  a  very  curious  fact  that  a  weak  sensation  of 
taste  of  one  kind  can  be  made  to  strengthen  a  taste 
of  another  kind.  If  two  glasses  of  water  be  equally 
sweetened,  one  of  them  can  be  made  to  appear  sweeter 


Smell  and  Taste  99 

by  adding  a  minute  quantity  of  quinine  powder. 
Vanilla  is  added  to  strengthen  most  of  the  flavours  of 
soda  water.  Some  partially  deaf  persons  can  liear  much 
better  in  the  midst  of  a  noise.  This  is  usually  ex- 
plained on  purely  physiological  grounds,  but  there  is 
a  possibility  of  an  explanation  on  the  ground  that  the 
mind  would  naturally  lump  in  a  very  weak  sensation 
of  any  kind  with  the  stronger  one. 

Some  of  the  peculiarities  of  flavours  are  due  to  feel- 
ings of  touch  on  the  tongue.  Soda  water  and  champagne 
stimulate  the  tongue  by  the  fine  bubbles  that  they  give 
off.  Pepper  and  mustard  produce  an  agreeable  irrita- 
tion. Puckery  substances,  such  as  raw  quinces,  act  as 
the  name  implies.  All  such  touch  sensations  are  not 
tastes,  although  they  and  the  smells  enter  into  the 
flavours  of  things. 

Sour  tastes  are  accompanied  by  touch.  This  can  be 
brought  out  clearly  in  a  series  of  experiments.  We 
begin  with  a  very  weak  solution  of  the  acid,  so  weak 
that  it  seems  like  water  when  tasted.  As  it  is  made  a 
trifle  stronger,  a  slight  puckery  feeling  first  appears, 
even  before  the  person  experimented  upon  notices  any 
sourness.  Bv  a  little  increase  in  the  streno;th  the  sour 
taste  is  made  to  appear  also.  When  the  sour  taste 
becomes  very  strong,  a  burning  sensation  is  felt  at  the 
same  time. 

When  we  begin  with  a  weak  solution  of  salt  and 
make  it  successively  stronger,  the  taste  appears 
first.  Later  a  weak,  burning  sensation  is  felt ;  this 
steadily  increases  but  never  overpowers  the  taste 
as  in  the  case  of  sour  things. 

With  a  solution  of  sugar  made  steadily  stronger  a 


loo        Thinking,  Feeling,   Doing 

feeling  of  softness  appears  before  the  taste.  Then  the 
taste  is  more  prominent.  With  a  very  strong  solution 
we  get  the  feeling  of  slipperiness  and  stickiness,  as  in 
honey  and  syrup.  With  saccharine  (an  intensely 
sweet  substance)  the  touch  sensations  are  present  but 
not  so  prominent. 

With  bitter  solutions  made  successively  stronger,  a 
fatty,  smooth  sensation  appears  before  the  taste. 
Thereafter  the  bitterness  is  most  prominent.  With 
pure  quinine  the  bitterness  overpowers  everything,  no 
matter  how  strong  the  solution.  With  quinine  sulphate 
or  chloride  the  very  strong  solutions  are  more  or  less 
burn  in 2". 

It  is  a  curious  but  uninvestigated  fact  that  tempera- 
ture likewise  has  an  influence.  Let  equal  quantities  of 
water  be  placed  in  two  tin  cups,  and  let  one  cup  be 
heated.  Then  if  the  same  quantity  of  lemon  juice  or 
any  sour  solution  be  dropped  into  each,  the  warmer 
solution  will  taste  sourer  than  the  cooler  one.  If  a 
sweet  solution  be  tried  in  the  same  way,  the  cooler 
solution  will  be  the  sweeier. 


CHAPTER  XI 

HEAKIXG 

AMONG  the  many  sounds  that  we  hear  we  generally 
make  a  classification  into  tones  and  noises. 
Pleasant  sounds,  like  those  of  a  flute,  we  call  tones ; 
unpleasant  ones,  like  those  of  escaping  steam,  rum- 
bling waggons,  or  screeching  parrots,  we  call  noises. 
This  is  only  a  convenient  way  of  sorting  sounds.  Yery 
many — if  not  most — sounds  are  either  tones  or  noises 
according  to  the  point  of  view.  A  jumble  of  piano- 
tones  is  a  noise.  The  scraping  of  a  violin  produces  a 
noise  in  the  hands  of  a  beginner  and  passes  gradually 
from  noise  to  tone  as  skill  is  acquired.  A  block  of 
hard  wood  when  struck  makes  a  noise :  yet  we 
call  the  same  sound  a  tone  when  the  block  of  wood  is 
one  of  the  notes  of  a  xylophone. 

In  a  simple  tone  three  properties  are  to  be  noticed  : 
(1)  pitch,  (2)  intensity,  (3)  duration. 

As  the  finger  is  slid  up  or  down  the  violin  string, 
we  hear  changes  in  the  pitch  of  the  tone.  As  the 
bow  is  drawn  harder  or  softer  against  the  string,  we 
hear  changes  in  the  intensity,  or  loudness.  As  the 
tone  is  continued  for  a  longer  or  shorter  time,  we 
hear  changes  in  duration. 

We   are   so   accustomed   to   saving^  that  tones   are 

loi 


I02         Thinking,  Feeling,  Doing 


"  high  ''  or  "  low,"'  that  there  seems  to  be  really  some- 
thing high  or  low  about  them.  We  might,  however, 
just  as  well  call  the  bass  tones  high.  This  naming 
of  the  tones  according  to  our  notions  of  space  is  derived 
from  the  Middle  Ages.  The  old  Sanskrit  terms  meant 
"  loud  "  and  "  soft"  ;  the  Hebrew  was  "audible  "  and 
"  deep  "  ;  the  Greek  was  "  low  "  and  "  high  "  in  exactly 
the  opposite  meaning  to  ours.  The  Latin  was  simply  a 
translation    of    the    Greek    words   for    "  acute "    and 

"grave";  and  the  modern  Ro- 
mance languages,  like  the  French, 
retain  the  Latin  terms.  In  the 
Middle  Ages  it  was  customary 
to  speak  of  ascending  and  de- 
scending the  scale;  it  is  from 
this  that  the  German  and  the  Eng- 
lish probably  derive  the  highness 
and  lowness  of  tones. 

Starting  from  the  middle  of  the 
piano,  run  the  scale  down  toward 
the  left.  The  lowest  tone  is  very 
deep  and  shaky.  Starting  again, 
run  the  scale  up  to  the  right  The 
high  tones  sound  shrill  and  tink- 
ling. What  would  happen  if  the 
piano  received  lower  and  lower 
tones,  or  higher  and  higher  tones, 
going  on  as  long  as  we  pleased? 
To  produce  tones  lower  than  the 
tones  of  the  musical  instruments  a  gigantic  tuning- 
fork  over  a  yard  long  has  been  made.  The  prongs 
are   furnished   with   weights.      As   the   weights    are 


Fig.  75— Giant  Fork  for 

Finding  the  Lowest 

Audible  Tone. 


Hearing 


103 


moved  toward  the  ends  the  tone  sinks  lower  and 
lower.  In  a  short  time  weak  puffs  are  heard  in 
addition  to  the  tone,  each  puff  corresponding  to 
a  single  movement  of  the  prongs.  Finally  the 
tone  disappears  entirely,  leaving  nothing  but  puffs. 
The  point  at  which  the  tone  disappears  is  called 
the  lower  Imiit  of  pitch,  or  the  threshold  of 
pitch. 

This  lower  limit  is  different  for  different  persons. 
It  is  generally  at  about  twelve 
complete  vibrations  per  second. 
Some  persons,  however,  have 
been  found  who  cannot  hear 
even  the  lower  tones  of  the 
piano.  Even  the  lowest  tone  of 
a  large  organ  at  thirty-two  vibra- 
tions per  second  seems  to  some 
persons  to  be  wavy. 

Going  upward  in  the  scale  we 
can  proceed  far  beyond  the  piano. 
The  test  can  be  made  with  a  set 
of  small  tuning-folks  or  small 
steel  bars.  It  is  most  conven- 
iently done  with  the  Gal  ton 
whistle  (Fig.  76).  This  whistle 
can  be  altered  in  length  by  a 
screw-cap.  As  it  is  made  shorter 
the  tone  rises.  By  means  of  a 
scale  marked  on  the  barrel  the 
pitch  of  the  tone  can  be  calcu- 
lated. 

The  highest  ^^udible  tone  h^s  been  found  to  be  very 


Fig.  76.— Whistle  for  Deter- 
mining the  Highest  Audi- 
ble Tone. 


i 


104         Thinking,  Feeling,  Doing 

different  for  difTcrent  persons.     To  some  persons  even 

tlie  liigliest  tones  of  tlie  ])iano    are    silent.      Others 

if:         again  can  liear  even   up  to  60,000   vibra- 

zz         tions   or  more  per  second.      The  position 

—  of  such  a  hig^h  tone  would   be  indicated 

—  by    the    musical    notation    given    in    the 

—  margin. 

^  Robert  Franz,  the  composer  of  the  music 

^         to   Bnrns's    My   Highland  Lassie^   in   1842 
^        lost  all  the  tones'  from  E^  upward  in  conse- 
quence of  the  whistle  of  a  locomotive.     In 
— ^  the  following  years  he  lost  two  half-tones 
-^         J   more,   so  that  in    1864  he  heard   nothing 
above  D'. 

The  sound  of  a  cricket  is  not  heard  by  some  per- 
sons. I  cannot  hear  the  squeak  of  a  bat  but  believe,  on 
authority,  that  it  does  make  a  sound.  Many  peo- 
ple cannot  hear  the  shrill  squeak  of  a  mouse.  When 
singing  mice  are  exhibited,  some  people  who  go  to 
hear  them  declare  that  they  can  hear  nothing,  others 
can  hear  barely  something,  and  others  again  can  hear 
much. 

It  has  also  been  noticed  that  as  a  person  grows  older 
he  loses  his  power  of  hearing  high  tones.  The  persons 
themselves  are  quite  unconscious  of  their  deficiency  so 
long  as  their  ability  to  hear  low  tones  remains  unim- 
paired. It  is  an  amusing  experiment  to  test  a  party 
of  persons   of    various    ages,    including   some   rather 

^  The  reader  is  reminded  that  the  successive  octa-^-es  of  the 
scale  are  indicated  by  small  figures.  Thus  C"^,  C-^  C°,  Cs  C=, 
etc. ,  indicate  the  successive  C's  of  the  scale ;  C'  is  middle  C. 
The  other  potes?  a-re  trea.ted  likewise, 


Hearing  105 

elderly  and  self-satisfied  personages.  They  are  indig- 
nant at  being  thought  deficient  in  the  power  of  hear- 
ing, yet  the  experiment  quickly  shows  that  they  are 
absolutely  deaf  to  shrill  notes  which  the  younger  per- 
sors  hear  acutely,  and  they  commonly  betray  much 
dislike  to  the  discovery.  Such  persons  should  be 
comforted  by  the  fact  that  every  one  has  his  limit. 
Sensitive  flames  have  been  found  to  be  powerfully 
affected  by  vibrations  that  are  too  rapid  for  ordinary 
ears. 

In  some  persons  the  upper  limit  of  pitch  is  very  low. 
It  is  related  of  Mr.  Cowles,  an  American  journalist, 
that  it  was  not  until  he  vras  twenty-five  years  of  age 
that  he  became  really  cognisant  of  his  defect.  Up 
to  this  time  he  had  treated  all  he  read  about  the  songrs 
of  birds  as  nothing  more  or  less  than  poetical  fiction. 
To  him  birds  were  perfectly  mute  ;  and  he  was  perfectly 
deaf  to  the  shrillest  and  highest  notes  of  the  piano, 
fife,  or  other  musical  instruments.  At  length,  after 
considerable  pains,  he  was  convinced  that  he  laboured 
under  some  defect  of  hearing.  When  put  to  the  test 
in  a  room  where  a  large  number  of  canary  birds  were 
singing  very  loudly,  he  declared  he  could  not  hear  the 
slightest  sound,  even  when  placed  close  to  their  cages. 
Moreover,  it  was  found  that  all  the  sibilant  sounds, 
such  as  s,  of  the  human  voice  were  equally  inaudible. 
In  all  other  respects  his  hearing  was  perfect. 

Galton,  the  inventor  of  the  whistle,  relates  that  he 
has  gone  through  the  whole  of  the  Zoological  Gardens, 
using  a  cane  with  a  whistle  at  one  end  and  a  bulb  at 
the  other.  He  held  the  cane  near  the  ears  of  the 
animals  alid  when  they  were  quite  accustomed  to  it  he 


io6         Thinking,  Feeling,  Doing 


would  blow  the  whistle.  Then  if  thej  pricked  their 
ears  it  showed  that  they  heard  the  whistle ;  if  they  did 
not  it  was  probably  inaudible  to  them.  Of  all  crea- 
tures he  found  none  superior  to  cats  in  hearing  shrill 
sounds ;  cats,  of  course,  have  to  deal  with  mice  and 
find  them  out  by  their  squealing.  A  cat  that  is  at  a 
very  considerable  distance  can  be  made  to  turn  its  ear 
around  by  sounding  a  note  that  is  inaudible  to  almost 
any  human  ear.  Small  dogs  also  hear  very  shrill 
notes,  but  large  ones  do  not.  At  Bern,  where  there 
appeared  to  be  more  large  dogs  lying  idly  about  the 
streets  than  in  any  other  large  town  in  Europe,  Gal- 
ton  tried  his  cane-whistle  on  them  for  hours  together 
but  could  not  find  one  that  heard  it.  Nearly  all  the 
little  dogs  he  met  would  turn  around. 

Curiously  enough  the  height  to  which  we  can  hear 

depends  on  the 
strength  of  the 
sound.  The  results 
of  specially  made 
experiments  are 
shown  in  Fig.  77. 
The  figures  at  the 
bottom  indicate  the 
relative  intensities  of 
the  blast  of  the 
whistle ;  thus  the 
strongest  tone  used, 
250,  was  five  times 
as  strong  as  50,  the 
weakest  one.  The 
figures  at  the  left  indicate  the  pitch  of   the  highest 


us. 


if» 


Fig.  77.— The  Highest  Audible  Tone  as  De- 
pendent on  Intensity. 


Hearing 


107 


audible  tone  for  six  different  persons.  At  50  for  the 
person  F  the  tone  was  lost  at  10,000  vibrations,  all 
above  that  being  unheard.  At  100  he  heard  to  about 
20,000  ;  at  150  to  27,000,  etc. 

Between  the  upper  and  lower  limits  of  pitch  the 
tones  do  not  advance  by  steps  as  in  the  piano  but 
continuously  as  in  tuning  a  violin  string.  In  other 
words,  there  is  an  unbroken  range  of  tone,  except  for  a 
few  defective  ears  where  portions  of  this  range  are 
lacking. 

What  is  the  least  difference  in  pitch  that  can  be 
noticed  ?  Suppose  that  a  violin  is  being  tuned  to 
another  one  or  to  a  pitch-pipe,  how  nearly  can  we  get 
it  to  an  exact  match?  The  fact  that  some  persons 
cannot  match  tones  as  well  as  others  is  made  plain  by 
a  few  trials. 

We  wish,  however,  to 
get  a  measurement  of  the 
exactness  to  which  we 
can  judge  tones,  or,  in 
other  words,  the  accuracy 
with  which  differences 
between  tones  can  be  de- 
tected. This  can  be  done 
by  comparing  a  tuning- 
fork  carrying  an  adjusta- 
ble weight  with  one  that 
remains  always  the  same. 

AS    ine    Weigni    is   movea        Finding  the  Least  Noticeable 
toward     the     ends    of    the  Difference. 

prongs,  the  tone  is  lowered  ;  as  it  is  moved  toward  the 
stem,  it  is  raised.  Such  a  pair  of  forks  is  shown  in  Fig.  78. 


loS         Thinking,  Feeling,  Doing 

Tlie  standard  fork  makes  the  same  sound  as  the 
weifjrhted  fork  when  the  weisrhts  arc  in  the  middle 
at  0.  The  standard  foi'k  is  first  sounded.  Then  after 
about  three  seconds  the  other  is  sounded.  The  person 
hearing  them  says  at  once  whether  he  can  detect  a 
difference  in  pitch  or  not.  If  he  says,  No,  the 
weights  are  moved  a  short  distance  toward  the  stem 
and  the  experiment  is  repeated.  This  is  continued 
till  he  detects  a  difference,  whereby  the  weighted 
fork  is  higher  than  the  standard.  This  difference  is 
called  the  least  noticeable  difference,  or  the  threshold 
of  difference. 

Instead  of  a  fork  with  adjustable  weights  a  series  of 
slightly  differing  forks  can  be  used.  To  pi-epare  such 
a  series  a  dozen  or  more  common  tuning-forks  all 
alike  are  obtained.  Tlie  pitch  of  a  fork  can  be  raised 
by  slightly  filing  the  ends  of  the  prongs;  it  can  be 
lowered  by  filing  tlie  prongs  near  the  stem.  Select 
one  of  the  forks  as  the  standard.  Strike  the  standard 
and  another  h^rk  at  the  same  time,  making  them  sound 
more  loudly  by  resting  them  on  the  table  or  liolding 
them  opposite  the  two  ears.  If  they  are  in  proper 
condition  a  single  smooth  tone  will  be  heaiil.  Now 
with  a  file  slightly  scrape  the  ends  of  the  two  prongs 
of  the  second  fork,  and  sound  them  again.  If  the 
filing  has  been  sufficient,  the  sound  now  heard  will 
not  be  smooth  and  even,  but  will  appear  to  wave 
between  weak  and  loud ;  often  the  forks  will  appear 
to  say,  "  wow-u-wow-u-wow-u,"  etc.  This  peculiar 
effect  is  called  a  beat.  It  is  known  that  the  number 
of  beats  in  one  second  is  the  same  as  the  difference  in 
the  number  of  vibrations  in  one  second.     By  counting 


Hearing  109 

the  beats  for  four  or  five  seconds  tlie  difference  be- 
tween the  two  forks  can  be  readily  determined.  If 
the  second  fork  is  too  high  in  pitch,  it  is  filed  more  at 
the  ends;  if  it  is  too  low,  it  is  filed  more  at  the  stem. 
In  this  manner  a  whole  set  of  forks  can  be  obtained, 
differing  by  slight  steps.  For  example,  a  convenient 
set  is  that  of  A'  =  435  as  a  standard,  with  the  other 
forks  436,  437,  etc.,  as  far  as  one  has  a  mind  to  go. 
The  preparation  of  such  a  series  is  somewhat  laborious 
and,  to  fulfil  all  requirements,  is  somewhat  expensive, 
owing  to  the  large  number  of  forks  needed  to  provide 
for  all  ears  from  the  finest  to  the  coarsest.  When  the 
series  is  complete,  the  standard  is  compared  with  each 
in  succession  in  the  same  way  as  with  the  adjustable 
fork  until  the  just  noticeably  different  fork  is  found. 

Just  as  the  threshold  of  difference  is  determined  for 
a  rise  in  pitch,  so  there  is  a  threshold  for  a  fall  in  pitch. 
The  weights  are  started  at  the  points  where  the  two 
forks  give  the  same  tone.  In  successive  experiments 
the  weights  are  moved  toward  the  ends  so  that  the 
tone  of  the  weighted  fork  is  repeatedly  lowered. 
Finally  the  difference  becomes  noticeable.  This  is 
the  point  at  the  threshold  of  difference  downward  in 
pitch. 

As  there  is  some  difficulty  in  finding  out  just  what 
the  pitch  of  the  fork  is  for  each  position  of  the  weights, 
and  as  the  performance  of  these  experiments  takes  a 
great  deal  of  time,  a  more  convenient  instrument, 
called  a  tone-tester,  has  been  devised.  It  consists  of 
an  adjustable  pitch-pipe  B  fastened  to  a  plate  A.  To 
the  regulating  rod  C  a  long  arm  D  is  fastened,  which 
is  moved  by  the  handle  E.     As  C  is  moved  inward 


no        Thinking,  Feeling,  Doing 

the  tone  of  the  pitch-pipe  rises.     As  it  is  moved  out- 
ward, the  tone  falls.    Each  movement  makes  a  change 


Fig.  79.— The  Tone-tester. 

in  the  position  of  the  pointer.  The  tone-tester  is  com- 
pared beforehand  with  a  carefully  tuned  piano  to 
determine  the  position  of  the  pointer  when  the  pipe 
gives  A  of  concert  pitch.  This  position  is  marked  at 
A  435  in  the  illustration.  The  figures  mean  that  at 
this  point  the  whistle  makes  a  tone  of  435  vibrations 
per  second.  In  the  same  manner  the  succeeding  notes 
are  settled.  The  spaces  are  then  subdivided  by  the 
eye  into  thirty-seconds  of  a  tone. 

To  make  the  experiment,  the  pointer  is  placed  at  A 
and  the  pipe  is  blown  for  an  instant.  The  pointer  is 
then  moved  upward  one  mark,  and  after  about  two 
seconds  the  pipe  is  again  sounded.  The  person  ex- 
perimented upon  tells  if  he  hears  a  difference.  The 
experiment  is  repeated,  starting  witli  A  every  time, 


Hearing 


III 


till  a  difference  is  heard.     In  a  similar  manner  the 
difference  below  A  is  found. 

In  experiments 
made  on  a  number 
of  New  Haven 
school-children  the 
accuracy  in  detect- 
insr  differences  was 

o 

found  to  increase 
with  age.  The  re- 
sults are  shown  in 
Fig.  80.  The  dis- 
tance along  the  bot- 
tom indicates  the 
age,  beginning  at 
six  and  ending  at 


Fig.  80.— Error  in  Hearing  Decreases  with  Age 

from  6  years  (at  the  left)  to  19  years 

(at  the  right). 


nineteen.    The  dis- 
tance upward  indicates  the  number  of  thirty -seconds 
of   a  tone  that   could   be   detected.     The   lower  the 
irregular  line  is,  the  more  acute  was  the  hearing  of 
the  children. 

There  is  another  and  perhaps  more  important  thresh- 
old to  be  found  than  the  threshold  of  difference, 
namely,  the  threshold  of  change.  Almost  all  the 
experiments  of  psychologists  have  been  confined  to 
the  threshold  of  difference ;  I  have  lately  called 
attention  to  this  threshold  of  change  and  to  the  fact 
that  it  is  an  entirely  different  thing  from  the  other. 

The  threshold  of  change  can  be  illustrated  by 
starting  the  tone  at  A  and  raising  or  lowering  it  con- 
tinuously till  a  difference  is  noticed.  I  have  succeeded 
in  proving  that  the   least  perceptible  change  varies 


112         Thinking',  Feeling,  Doing 

with  tlic  rate,  as  for  pressure  and  temperature  (})p.  80, 
90),  but  have  not  been  able  to  accurately  determine 
the  relation. 

There  is  another  mental  fact  closely  related  to  the 
tlireshold  of  difference  but  not  quite  identical  with  it, 
namely,  the  accuracy  of  tone-judgment.  Suppose  we 
have  two  forks  almost  but  not  quite  alike  in  })itch.  If 
we  sound  them  in  succession,  we  sometimes  detect  the 
difference,  sometimes  not.  It  is  evident  that  for 
the  same  pair  of  forks  the  sharper  ear  will  detect 
the  difference  more  frequently  than  the  duller  ear. 

The  experiment  is  performed  in  the' following  way. 
Three  forks  are  provided ;  two  of  them  are  exactly 
alike,  the  third  is  slightly  different.  The  person 
tested  is  seated  with  his  back  to  the  experimenter. 
The  experimenter  strikes  two  forks  in  succession  ;  the 
person  tested  says  at  once  whether  they  are  the  same 
or  different.  Suppose  he  says.  Different ;  if  they 
were  really  different  the  experimenter  records  one 
right  answer.  Suppose  he  says,  Same ;  if  they  were 
really  different  the  experimenter  records  one  wrong 
answer.  No  record  is  made  of  the  experiments  with 
the  two  forks  that  are  really  the  same,  as  they  are 
introduced  merely  to  avoid  prejudice  on  the  part  of  the 
person  experimented  upon.  The  experimenter  finally 
counts  up  the  total  number  of  experiments  with  the 
two  really  different  forks  and  the  number  of  correct 
answers  to  these  forks.  For  example,  if  there  were 
twenty-five  experiments  in  which  the  different  forks 
were  used  and  fifteen  correct  answers,  the  accuracy  of 
judging  this  particular  tone-difference  can  be  stated  for 
this  particular  person  as  ^i,  or  60  per  cent.     With  a 


Hearing 


H3 


greater  difference  between  the  two  tones  tlie  percentage 
of  correct  answers  will,  of  course,  be  greater.  By 
using  the  same  difference  the  relative  accuracy  for 
different  persons  can  be  ascertained. 

The  threshold  differs  greatly  for  different  persons. 
Fine  ears  have  been  found  that  will  detect  a  difference 
of  less  than  half  a  vibration  in  tones  between  B"  = 
120  and  B"  =  1,000.  Such  observers  can  distinguish 
over  1,200  different  tones  within  the  octave  B'  to  B^ 

On  the  other  hand,  it  is  not  uncommon  to  meet 
persons  who  can  hardly  distinguish  two  neighbouring 
tones.  In  fact,  one  case  is  reported  of  a  well-educated 
man  who  had  been  unable  to  learn  music  in  any  way. 
It  was  found  that  he  could  not  tell  the  difference 
between  any  two  neighbouring  tones  of  tlie  piano. 
Between  the  lowest  tone  and  the  hio-hest  he  found  a 
very  great  difference,  but  when  the  scale  was  run  from 
one  end  to   the  other  the  change  of   tone  appeared 


Fig.  si.— Apparatus  for  Finding  tlie  Middle  Tone. 


continuous  and  not  by  steps.     In  the  middle  regions 
of  the  scale  he  could  not  tell  apart  tones  forming  an 

8 


114         Thinking,  Feeling,  Doing 

interval  less  than  a  third ;  in  tlie  u[)per  and  lower 
regions  the  interval  had  to  be  a  septime,  an  octave,  or 
sometimes  something  still  greater. 

If  a  low  tone  be  sounded,  then  a  medium  one,  and 
then  a  high  one,  we  can  tell  whether  the  middle  one  is 
half  way  between  the  two  extremes  or  not.  Musical 
instruments  cannot  well  be  used  for  this  experiment  as 
their  tones  are  not  simple  but  very  complex  ;  they 
introduce  great  errors  into  the  result.  By  using 
tuning-forks  perfectly  pure  tones  are  obtainable. 

The  arrangement  for  this  experiment  is  shown  in 
Fig.  81.  Three  tuning-forks,  1,  2,  3,  are  placed  before 
adjustable  boxes,  or  resonators,  I,  II,  III.  From  each 
resonator  a  rubber  tube  leads  to  a  general  tube  s  which 
runs  through  double  walls  2  to  a  distant  room  where 
the  person  experimented  upon  puts  the  end  0  to  his  ear. 

In  front  of  each  box  there  is  a  movable  cover  which 
can  be  pulled  aside  by  a  string.  Suppose  the  forks  are 
sounding,  the  observer  in  the  distant  room  hears  no- 
thing till  one  of  these  covers  is  pulled  aside. 

Fork  1  is  selected  as  a  low  fork,  fork  3  is  selected 
as  a  higher  one,  and  fork  2  is  adjustable  by  weights. 
The  forks  are  sounded  in  succession,  1,  2,  3  or  3,  2,  1. 
The  observer  tells  whether  fork  2  is  properly  adjusted 
to  be  in  the  middle  or  not. 

The  results  indicate  that  our  estimates  do  not  fol- 
low the  musical  scale.  For  example,  if  the  extreme 
tones  be  C^  ^  256  vibrations  and  C^  =  512  vibra- 
tions, the  middle  chosen  will  on  the  average  be 
G^  ==  3S4  vibrations.  This  is,  counting  by  vibrations, 
just  half  way,  but,  according  to  our  musical  scale,  it  is 
nearer  the  upper  tone.     Likewise,  if  the   extremes  be 


Hearing 


115 


Ci  =  256  and  C3  =  1,024,  the  middle  will  be  about 
C2  =  840  and  not  C^  =512- 

Let  us  now  turn  to  a  study  of  the  intensity  of  tones. 
The  first  requirement  is  a  tone  whose  intensity  can  be 
varied.  The  simplest  plan  is  to  use  an  electric  tun- 
ing-fork with  an  induction  coil  (Fig.  82).  A  magnet 
between  the  prongs  of  the  fork  keeps  it  in  motion  elec- 
trically. The  electric  current  is  broken  at  every  vibra- 
tion of  the  fork.  As  it  passes  through  the  wire  coil, 
it  sets  up  electrical  currents  in  the  other  wire  coil  near 
it.  When  a  telephone  is  connected  to  this  second  coil, 
a  tone  can  be  heard  by  placing  the  telephone  to  tlie 
ear.  This  tone  can  be  weakened  by  moving  the  second 
coil  away  from  the  first  one. 


Fig.  82.— Finding  the  Threshold  of  Intensity  for  Hearing. 

The  person  to  be  tested  puts  tlie  telephone  to  his  ear. 
The  second  coil  is  placed  far  from  the  first ;  no  sound 


ii6         Thinking,  Feeling,  Doing 

is  heard.  It  is  gradually  moved  nearer  till  the  tone  is 
heard.  The  distance  apart  is  noted.  Then  it  is  placed 
close  to  the  first  coil,  a  load  tone  being  heard,  and  is 
gradually  mo\x'd  away  till  the  tone  is  lost.  The 
average  of  the  two  results  gives  a  figure  for  the  deaf- 
ness of  the  person. 

For  rough  tests  a  watch  is  often  used.  The  watch 
is  steadily  brought  nearer  to  one  ear  (the  opposite 
one  being  closed)  till  the  tone  is  heard.  The  distance 
of  the  watch  from  the  ear  indicates  the  threshold  for 
sound,  or  the  degree  of  deafness.  This  method  is  very 
unreliable,  the  chief  difficulty  being  the  disturbance 
by  outside  noises. 

A  special  notation  has  been  invented  to  indicate 
tones.  The  first  complete  notation  for  pitch  is  attributed 
to  Guido  Aretino  in  the  eleventh  century.  Three  cen- 
turies later  the  notation  for  duration  was  introduced  by 
Jan  de  Meurs.  Naturally  the  presence  of  exact 
means  of  expression  for  these  two  quantities  afforded 
opportunity  for  progress  in  the  artistic  execution  on 
the  one  hand  and  for  scientific  research  on  the 
other.  The  subject  of  pitch  has  reached  a  high  de- 
gree of  development.  The  duration  of  tones  is  also 
a  matter  of  technique  that  has  been  carried  to  a  great 
degree  of  precision  in  practice. 

We  are  all  familiar  with  the  staff  notation  for  pitch 
and  duration.  Each  note  indicates  a  certain  tone  of  a 
definite  pitch  lasting  through  a  definite  time. 

The  intensity  of  tones  has  been  neglected  ;  it  must 
be  remembered  that  we  are  not  speaking  of  the  semi- 
conscious use  of  the  different  degrees  of  intensity  in  the 
execution  of  a  piece  of  music,  but  to  a  deliberate  use  of 


Hearing 


117 


the  shades  of  intensit}'.  lu  music  the  consideration  is 
confined  to  the  five  vague  expressions,^,/  m^  p^  pp. 
When  a  group  of  tones  is  to  be  made  rather  loud,  put 
an/over  it.  How  loud?  just  as  the  performer  feels. 
All  of  the  same  loudness?  just  as  the  performer  is  in- 
clined. Are  all  the  tones  without  these  letters  to  be  of 
the  same  strength?  just  as  the  performer  is  disposed. 
These  five  vague  grades  cover  only  a  few  tones  out  of 
the  thousands  in  a  piece  of  music.  The  composer  is 
powerless  to  give  any  indication  of  the  wonderfully  del- 
icate shadings  in  the  intensity  of  the  different  members 
of  a  group  of  tones ;  the  performer  is  left  without  help. 
Two  good  performers  on  the  organ  will  execute  the 
same  music  witli  utterly  different  effects,  because  they 
do  as  they  please  with  the  intensity  of  the  tones. 
AVhich  effect  did  the  composer  intend?  Nobody 
knows. 

It  is  to  overcome  this  difficulty  that  I  propose  a  sys- 
tem of  notes  to  include  shades  of  intensity.  Suppose, 
for  the  present,  that  we  agree  upon  nine  grades  of  in- 


^    r 


n 


Fig.  83,— Method  of  Indicating^  Intensity  in  Notes  ;  Loudest  by  Black, 
Weakest  by  White. 

tensity  between  the  weakest  and  the  strongest  the 
instrument  is  successfully  capable  of.  Then  we  can 
introduce  a  system  of  shading  the  heads  of  the  notes  to 
indicate  grades  of  intensity  just  as  the  heraldist  uses 
shading  to  indicate  colours.  Such  a  system  is  shown 
in  Fiff  8S. 


The  head   of    the  note 


ought  not 


to   be  used   to 


ii8         Thinking,  Feeling,  Doing 

indicate  duration.  In  the  present  system  dura- 
tion  is   shown   by  the    hooks  on    the   stems   of    the 

m  notes,  except    in    the    case  of  the   whole 

if  and  half-notes,  where  a  difference  is  made 

#  in   the   head    of    the   note.     This  change 

\  in  the  head  of  the  note  is  unnecessary  for 

|#  the  indication  of  duration  and  can  be  em- 

I  ployed  to  indicate  intensity.     A  very  slight 

0  change  is  thus  necessary  in  the  present  no- 

V  tation  ;  we  can  retain  the  usual  method  of 
1^  indicating  pitch    and    the    usual  signs  for 

V  duration  with  the  exception  of  the  two  for 
p  the  whole  note  and  the  half-note.  These  can 
y^  be  indicated  by  two  lines  across  the  stem  of 

the  ordinary  quarter-note  for  the  whole  note 

Fig.  84.— Series         ^  p  ,        i     i  ^  ^  i 

of  Notes  Ac- and  one  lor    the  halt-note.     Consequently 

cording     to  .  i       i  •  -ii 

Duration,  the  scrics  of  notcs  as  regards  duration  wi.l 
be  that  shown  in  Fig.  84,  representing  the  whole,  half, 
quarter,  eighth,  sixteenth,  and  thirty-second  notes 
respectively. 

Now  we  can  use  the  head  of  a  note  to  indicate  its 
intensity,  and  even  its  form.  Suppose  we  wish  to 
indicate    a   half-note    of   medium   constant  intensity, 

we  have  P  ;  or  an  eighth-note  of  loud  intensity  and 
staccato  form,  r  ;  or  a  whole  note,  weak,  but  of  cres- 
cendo form,  U ^ 

Where  are  the  tones  we  hear  ?  With  one  ear  closed 
the  sounds  we  hear  have  no  definite  position.  We 
know  that  a  certain  rattling  must  be  down  on  the 
street,  because  waggons  cannot  be  up  in  the  air  :  the 


Hearing  119 

song  of  a  bird  cannot  be  under  our  feet.  But  a  plain 
tone  is  nowhere,  or  rather,  anywhere.  Take  a  seat  in 
this  high-backed  chair ;  let  some  one  hold  your  head 
firmly  so  that  you  cannot  turn  it.  Put  your  finger 
tightly  in  one  ear  and  close  your  eyes.  Now  I  make 
clicks  with  a  snapper  sounder,  or  I  strike  a  glass  with 
a  spoon.  Point  to  where  the  sound  is.  If  I  vary  the 
intensity  of  the  sound  so  that  you  cannot  reason  the 
the  matter  out,  your  answers  are  generally  wrong. 

By  turning  the  head  you  can  get  an  idea  of  the 
place  because  you  know  that  sounds  straight  out  side- 
wise  are  stronger  than  in  any  other  direction. 

Open  both  ears  but  keep  the  eyes  closed.  Now  you 
can  tell  me  just  where  the  sound  is.  You  draw,  un- 
consciously, an  inference  from  the  relative  intensity  of 
the  two  sounds  from  the  two  ears.  But  whenever  I 
snap  the  sounder  equally  distant  from  the  two  ears, 
you  are  always  wrong.  Imagine  a  sheet  of  glass 
passed  through  the  body  dividing  it  into  two  halves 
symmetrically.  For  all  sounds  in  this  plane  you  are 
utterly  at  a  loss.  I  snap  my  sounder  under  your  chin ; 
you  declare  that  it  is  behind  your  back.  I  snap  it  at 
your  feet ;   you  say  it  is  in  front  of  your  nose. 


CHAPTER  XII 


COLOUR 


w 


THE  number  of  different  colours  that  we  can  dis- 
tinguish in  nature  probably  amounts  to  several 
hundred  thousand.  Suppose  we  had  all  of  them  to 
arrange  in  a  consistent  system.  We 
find  amono;  them  a  series  of  colours 
ranging  from  white  through  gre)'^  to 
black,  that  show  no  traces  of  red,  green, 
blue,  or  other  of  the  what  we  have  been 
accustomed  to  regard  as  the  specific 
colours.  These  are  the  "  neutral " 
colours.  With  white  at  one  end  and 
black  at  the  otlier  all  the  neutral  colours 
including  the  greyish  wliites,the  medium 
greys  and  the  greyish  blacks  would  be 
indicated  by  points  along  a  line  (  WBk^ 
Fig.  85). 

Now  let  us  pick  out  all  the  brightest 
and  purest  colours  and  arrange  them  by 
likeness.  Beginning  with  red  we  put 
ncKt  to  it  a  slightly  different  red,  again  a  slightly  dif- 
ferent one,  and  so  on  ;  soon  we  find  that  we  have  passed 
to  orange.  From  orange  we  pass  to  yellow,  then  to 
green,  blue,  and  purple.  If  we  use  several  hundred 
different  colours,  the  differences   between   successive 


Fig.  85.— System  of 
Greys  or  Neu- 
tral Colours. 


1 20 


Colour 


121 


ones  will  be   almost    imperceptible.     We    note    that 
beyond  purple  the  colours  become  reddish  until  we 


T/NTS 


Fig.  86.— System  of  the  Brightest  Colours  and  the  Tints. 

reach  the  original  red.  Such  a  system  of  the  brightest 
colours — or  "  hues  " — might  be  a  square  or  a  pentagon 
or  any  other  arbitrary  closed 
figure.  Let  us  choose  the 
curve  shown  in  Fig.  86 ;  the 
reason  for  the  choice  will  be 
given  later.  The  letters  on 
the  curve  indicate  the  colours, 
red,  orange,  yellow,  green, 
blue,  and  purple.  The  term 
*'  violet "  is  often  used  instead 
of  purple,  but  this  is  not  re- 
commended. 

The  greys  (Fig.  85)  and  the 
brightest  colours  (Fig.  86) 
are  only  a  few  out  of  the 
vast  number  before  us. 
Starting  with  any  colour,  say  red,  we  can  pass  by 
small  steps  through  whitish  red  (or  pink)  to  white 
without  a  trace  of  any  other  colour ;  such  whitish 
colours  are  called  "tints."     We  can  do  the  same  from 


Fig.  87.— Systems  of  Greys, 

Shades,   Greyish    Tints 

and  Greyish  Shades. 


122         Thinking,  Feeling,  Doing 

orange,  yellow,  etc.,  or  from  any  one  of  the  brightest 
colours.  To  indicate  this  we  place  white  in  the  mid- 
dle of  the  closed  curve  (Fig.  86)  and  place  each  one 
of  the  tints  on  aline  from  white  to  its  respective  hue. 
In  a  similar  way  we  find  "  shades  "  of  each  colour 
passing  imperceptibly  to  black,  and  finally  "  broken  " 
tints  and  shades  passing  imperceptibly  toward  every 
degree  of  grey.  Thus  for  red  we  would  construct  a 
diagram  like  that  in  Fig.  87.  This  we  have  to  do  for 
every  hue. 


Fig.  88.— System  of  all  the  Colours. 


The  entire  system  of  the  colours  will  be  represented 
by  a  solid  figure  (Fig.  88)  whose  axis  is  taken  from 
Fig.  85,  whose  top  from  Fig.  86  and  whose  content  is 
made  no  of  systems  like  that  of  Fig.  87  made  for  every 


Colour 


12 


hue.     Each  colour  in  nature  will  be  represented  by  a 
point  within  this  figure. 

Many  colours  can  be  produced  by  mixture.    This  can 
be  conveniently  done  by  disks  on  a  colour- top  (Fig.  89), 
or  a  colour-wheel  (Fig.  90). 
Each  disk  has  a  hole  exactly 
m   the  centre,   and  a  radial 
slit.     To  put  two  disks  to- 
gether they  are  slid  over  each 
other  by  means  of  the  slits 
(Fig.    91).      They   are   then 
placed  on  the  axle  of  the  top       Fio.so.-The  coiour-top. 
or   the    wheel    and    rotated 
rapidly.     The  colours  combine  for  the  eye.     Different 


Fig.  90.— The  Colour-wheel. 

colours  are  produced  by  adjusting  the  proportions  of 
the  two  disks  that  are  exposed ;  when  a  desired  colour 
is  obtained,  the  amounts  are  read  off  by  applying  a 
scale  (Fig.  92).  Some  colours  require  only  two  disks ; 
others  require  more. 

The  greys  can  be  produced  by  using  white  and  black 
disks  in  various  proportions. 


124        Thinking,  Feeling,  Doing 


The  colours  must  now  be  accurately  defined. 

The  standard  white  light  is  that  wliich  reaches  the 
earth's  surface  at  mid-day  from  the  sun  in  a  cloudless 
sky.  A  pure  white  }3igment,  that  is,  one  that  reflects 
the  standard  white  practically  untinged  with  any  hue, 
is  found  in  magnesium  oxide ;  this  can  be  readily  pro- 


FiG.  91.— Putting  Two  Disks 
Together. 


Fig.  9a.— Two  Disks  with  Scale. 


duced  by  burning  a  strip  of  magnesium  tape  so  that 
its  white  smoke  is  deposited  on  a  piece  of  metal  or 
mica. 

When  an  opaque  object  is  placed  in  front  of  a  white 
surface,  a  grey  shadow  is  produced  ;  it  becomes  darker 
as  the  light  is  more  completely  intercepted.  The 
interception  of  all  light,  as  in  a  perfectly  darkened 
room,  leaves  blackness.  All  objects,  even  the  blackest, 
reflect  some  light;  the  nearest  approach  to  a  surface 
that  will  appear  perfectly  black  when  illuminated  is 
attained  by  lining  the  bottom  and  sides  of  a  cylinder 
with  black  velvet. 

The  purest  colours — that  is,  the  brightest  hues  with 
the  least  whitishness — are  found  in  the  spectrum.  This 


Colour 


125 


is  a  band  of  colour  that  may  be  produced  by  placing  a 
grating  (Fig.  93)  or   a  prism,  in  a  beam  of  sunlight. 

The  radiations  from  the 
sun  consist  of  vibrations  of  the 
optical  ether.  The  spectrum 
comprises  the  vibrations  be- 
tween 760  and  380  millimi- 
crons long.  A  millimicron  is 
the  millionth  part  of  a  milli- 
meter. 

With  the  spectrum  we  can 
perform  more  accurate  ex- 
periments in  mixing  colours 
than   with   the    colour   disks. 

We  must  note  the  following 
results. 

White  can  be  produced  by 
using  any  hue  of  the  spectrum 
and  one  other  hue  in  the 
appropriate  intensities.  Two 
hues  that  can  be  thus  used  are 
called  "complementary  colours." 
plementary  colours  are  : 

red  656  — 

orange  608  — 

yellow  567  — 

greenish  yellow  564:  


Fig.  93.— Spectrum  from  a 
Grating. 

Some  of  the  com- 


greenish  blue  492 


blue  490 

purplish  blue  405 

purple       433 

The  figures  indicate  millimicrons.  Fig.  86  is  so  con- 
structed that  complementary  colours  lie  at  the  opposite 
ends  of  lines  drawn  through  W  and  at  such  distances 
from  TFas  indicate  the  amounts  of  each  hue  required 
for  the  mixture  to  make  white  with  its  complementary* 


126         Thinking,  Feeling,  Doing 

When  colours  not  complementary  are  used,  tlie 
results  depend  on  the  proportions.  Red  and  yellow- 
ish green  give  all  the  variations  through  reddish  orange, 
orange-red,  orange,  orange-yellow,  yellowish  orange, 
yellow,  and  greenish  yellow.  These  colours  lie  on 
the  straight  portion  at  the  left  of  the  curve  in  Fig.  86. 
Red  and  purple  give  all  the  intermediate  purples ;  these 
colours  lie  along  the  straight  line  at  the  bottom  of  the 
same  curve.  Red  and  green  give  all  the  variations 
through  orange  and  yellow,  but  they  are  all  whitish  ; 
they  lie  along  a  straight  line  drawn  from  red  to  green, 
which  passes  nearer  to  white  than  the  line  from  red  to 
yellowish  green.  To  find  what  are  the  results  of  com- 
bining any  two  colours  a  line  is  drawn  between  their 
positions  in  Fig.  86  and  the  character  of  the  resulting 
colours  is  noted. 

Three  colours  can  also  be  combined  by  disks  or 
spectrum  colours.  The  result  is  the  same  as  if  two 
had  been  first  combined  and  then  the  third  added. 
The  position  in  the  colour  diagram  of  Fig.  86  is  worked 
out  in  the  same  way. 

By  using  three  spectrum  colours,  red,  green,  and 
purple,  we  can  produce  nearly  all  the  hnes  of  the 
spectrum  with  fair  approximation.  This  suggests  that 
the  system  of  colours  may  be  reducible  to  three  ele- 
mentary colour-sensations.  These  sensations  cannot 
be  colours  of  the  spectrum  because  the  results  of  spec- 
trum mixture  are  generally  somewhat  whitish. 

The  study  of  abnormal  forms  of  colour  vision  known 
as  colourblindness  (see  below)  indicates  that  our  three 
fundamental  sensations  are  far  more  saturated  colours 
than  those  we  find  in  the  spectrum  ;  the  green  in  par- 


Colour  127 

ticular  is  a  far  purer  green  than  we  ever  actually  see, 
the  green  of  the  spectrum  being  very  whitish.  The 
red  is  not  verj^  different  from  the  end-red  of  the  spec- 
trum but  the  other  colour  is  a  deep  indigo-blue  and 
not  a  purple.  These  fundamental  sensations  find  places 
in  the  colour  diagram  at  the  corners  of  the  large 
triangle  in  Fig.  9-i. 

Creen 


i^  Blue 

Fig.  94.— The  Colour  Triangle. 

The  combinations  of  pigments,  such  as  paints,  often 
give  very  different  results  from  the  combinations  of 
the  colours.  If  we  mix  the  paints  with  which  two 
paper  disks  have  been  coloured,  a  paper  coloured  by 
the  mixture  will  never  be  of  the  same  colour  as  the 
resultant  from  a  direct  mixture  of  the  colours  of  the 
two  disks  by  means  of  the  colour-top. 

This  can  be  illustrated  by  a  disk  prepared  as  in  Fig. 
95.  The  shaded  portions  are  to  be  painted  with  blue, 
the  light  portions  with  yellow,  and  the  central  portion 
with  a  green  formed  by  a  mixture  of  half  blue  and 
half  yellow.  When  the  disk  is  rotated,  the  blue  and 
yellow  directly  mixed  never  produce  green  but  a  grey- 
ish colour  with  a  blue  or  yellow  cast. 


128         Thinking,  Feeling,  Doing 

When   increasing   quantities   of   yellow  paint    are 
mixed  with  the  blue  paint,  the  colour  passes  through 
y  various  shades  of  bluish  green,  green, 

and  yellowish  green.     When  yellow 
\a  and  blue  colours  are  mixed,  the  re- 
sulting colour  passes  through  greyish 
fb  blue,  grey,  and  greyish  yellow.   With 
some  blues  the  grey  has  a  very  slight 
T.     n^    ,T-  •    V  11     sreenish  tinp^e. 

Fig.  95.  —Mixing  Yellow  o  o 

and  Blue.  IlX^q  rcason  wliy  blue  and  yellow 

pigments  give  green  can  be  illustrated  by  using  blue 
and  yellow  glass.  When  two  such  pieces  of  glass  are 
placed  together,  all  light  passing  through  both  of  them 
is  green.  Blue  glass  is  blue  because  the  glass  absorbs 
the  red,  orange,  and  yellow  light  and  allows  the  blue 
light  to  pass.  Yellow  glass  absorbs  the  blue  and 
allows  the  red,  orange,  and  yellow  to  pass.  Each  of 
them  allows  a  portion  of  the  green  to  pass.  When 
both  of  them  are  together,  the  blue  keeps  out  the  red, 
orange,  and  yellow,  while  the  yellow  keeps  out  the 
blue.     Consequently  only  the  green  gets  through. 

Blue  paints  are  blue  because  the  minute  particles  of 
which  they  are  composed  send  back  to  the  eye  mainly 
colours  from  the  blue  end  of  the  series  of  hues.  Yel- 
low paints  send  back  mainly  those  from  the  red 
end.  Both  send  back  some  green.  When  they  are 
mixed,  the  blue  paint  absorbs  all  the  red  end  and  the 
yellow  absorbs  all  the  blue  end,  leaving  only  green  to 
be  sent  back.  Similar  results  are  obtained  from  the 
other  paints ;  their  mixtures  are  matters  depending  on 
their  particular  composition  and  not  on  their  colours. 

These  accidents  of  the  action  of  paints  formerly  led 


Colour  129 

people  to  suppose  that  colours  followed  the  same  laws. 
Thus  red,  yellow,  and  blue  were  formerly  called  the 
fundamental  colours.  The  artist  often  speaks  of  his 
paints  as  his  "colours;"  his  laws  of  combination 
of  the  fundamental  "  colours  "  are  quite  correct,  if  by 
"  colours  "  we  understand  paints.  To  avoid  confusion 
with  the  other  use  of  the  word  colour,  it  is  preferable 
not  to  use  it  to  mean  paint  or  pigment.  Red,  yellow, 
and  blue  are  the  fundamental  pigments,  and  red, 
green,  and  blue  are  the  fundamental  colours. 
9 


CHAPTER  XIII 

COLOUR   SENSITIVENESS 

WE   are   frequently   called   upon   to   distinguisli 
small  differences  in  colour;  how  accurately 
can  we  do  it? 

The  colour-top  furnishes  one  method  of  answering 
the  question.  Suppose  we  take  as  a  definite  question  : 
How  accurately  can  we  judge  the  mixture  of  small 
portions  of  blue  with  a  large  mass  of  red?  The  little 
red  disk  is  placed  in  the  centre  of  the  top  ;  it  remains 
unchanged  during  the  experiment.  The  large  red  and 
blue  disks  are  placed  together  so  that  a  minute  por- 
tion of  the  blue  appears.  The  top  is  spun  ;  no  differ- 
ence is  detected.  A  little  more  blue  is  added  and  the 
top  is  again  spun.  This  is  repeated  till  the  difference 
is  noticed.  The  amount  of  blue  can  be  measured  by 
the  graduated  disk  (Fig  92).  Suppose  it  covers  y^^ 
of  the  whole  circle.  The  red  must  cover  -^W,  or  nine 
times  as  much  as  the  blue.  Therefore  we  can  add 
one  part  of  blue  to  nine  of  red  before  the  difference  is 
detected. 

The  result  depends  upon  the  sensitiveness  of  the 
person.  A  dyer  will  detect  minute  differences  that 
escape  ordinary  individuals;  persons  who  have  paid 
little  attention  to  art  are  often  incapable  of  detecting 
large  differences, 

130 


Colour  Sensitiveness  131 

There  are  persons  for  whom  the  hues  of  the  spec- 
trum can  be  approximately  matched  by  combinations 
of  less  than  three  colours  ;  such  persons  are  commonly 
said  to  be  "colour  blind." 

To  show  the  differences  in  different  persons  two 
smaller  disks,  white  and  black, 
lu  and  d^  should  be  placed 
over  the  larger  disks,  R,  G  and 
^(Fig.  96).  Tlie  white  and 
black  make  a  grey,  and  the 
larger  disks  should  be  adjusted 
to  make  a  grey  also.  A  finer 
adjustment  is  obtained  by 
making  both  greys  alike.  FiG.96.-Getting  the  Grey 

The  relative  proportions  of 
IV  and  d  may  be  disregarded  and  grey  in  general  may 
be  indicated  by  m.    Suppose  one  person  gets 

m  [=60  w+40  c^]=35  i?+30  (?+36  B 
and  another 

m=b  i?+45  G+m  B 

It  is  evident  that  the  second  one  is  much  less  sensitive 
to  red;  in  fact,  such  a  person  would  be  called  red-blind. 

Roughly  speaking,  humanity  falls  into  four  great 
classes:  the  trichromats ;  the  dichromats  of  two  kinds, 
and  the  monochromats. 

Trichromats  form  about  ninety-five  per  cent  of  the 
males  and  almost  all  the  females.  The  colours  they 
see  can  be  produced  by  combinations  of  three  funda- 
mental colours,  red,  green,  and  blue.  The  relative 
proportions  are  mdicated  in  Fig.  97. 

The   dichromats  form  about  five  per  cent,   of  the 


132         Thinking,  Feeling,  Doing 


males.  The  colours  tliey  see  can  be  formed  from  two 
fundamental  colours  which  we  may  call  "  warm  "  and 
"cold." 


100  eSO  600  SSO  SOQ  ^SO  fOO 

^       B     C  D  Eh     F  Q       H 

Fig.  97.— Trichromats.     Proportions  of  the  Fundamental 
Colours  in  the  Spectrum  Colours. 

It  may  be  regarded  as  settled  that  the  "  cold  "  colour 
is  the  same  as  the  blue  of  the  three-colour  persons.  The 
"  warm  "  colour  has  been  supposed  to  be  gve^n  in  one 
case  and  red  in  the  other ;  the  two-colour  persons  are 
thereforeusually termed  "red-blind"  or  "green-blind." 
It  is  probable,  however,  that  the  warm  colour  is  yellow. 

The  proportions  of  the  two  fundamental  colours, 
"warm  "  and  blue,  required  to  match  the  hues  of  the 
spectrum  are  indicated  for  the  first  form  of  dichromasy 
in  Fig.  98.  On  the  assumption  that  the  warm  colour  is 
yellow  the  spectrum  appears  to  begin  with  a  dark 
yellow  (700  millimicrons),  change  to  bright  yellow  (600 
millimicrons),  pass  through  whitish  A'ellow  to  white 
(500  millimicrons),  then  to  whitish  blue  and  blue 
(450  to  400  millimicrons). 


Colour  Sensitiveness 


^33 


For  the  second  from  of  clicliroinasy  the  distribution 
of   the    two    colours   is   shown  in    Flo-.    99.     On  the 


7*0  eso  600  sso  soo  ^50 

B    C  D  Eire 

Fig.  98.— Dichromats  of  the  First  Class.     Proportions  of  the 
Fundamental  Colours  in  the  Spectrum  Colours. 


4^0 

H 


assumption  that  the  warm  colour  is  3^ellow  a  large  part 
of  one  end  of  the  spectrum  appears  as  a  very  dark 
yellow.  The  colour  then  changes  to  bright  yellow 
(550),  whitish-yellow,  white  (500),  whitish-blue  and 
blue  (450). 

Since  all  the  colours  of  nature  are  derived  from  the 
solar  spectrum,  the  dichromtitic  person  sees  the  world 
as  combinations  of  the  two  colours,  yellow  and  blue; 
red,  orange,  and  green  are  unknown  sensations.  The 
various  colours  that  he  has  been  taught  to  call  by  tlie 
names  red,  green,  etc.,  are  to  him  varieties  of  yellow. 
The  strawberry  and  its  leaves  are  both  shades  of 
yellow ;  a  dark  leaf  cannot  be  distinguished  from  a 
berry.  For  the  same  reason  a  piece  of  sealing  wax 
(red  to  the  trichromat)  ap[")cars  of  nearly  the  same  colour 
as  grass.     An  orange,  a  lemon,  or  a  beet,  differ  only  in 


134         Thinking,  Feeling,  Doing 


shade  from  spinach.  The  two  classes  of  dichromats 
differ  in  seeing  these  objects  in  different  shades  of 
yellow. 


100  eso 

e.     B    c 


eoo 
D 


550 


SCO 


f£0 


EJ,         F 


4-00 

H 


Fig.  99. — Dichromats  of  the  Second  Class.     Proportions  of  the 
Fundamental  Colours  in  the  Spectrum  Colours. 


Three  other  forms  of  colour  vision  arise  from  the  loss 
of  one  of  the  three  fundamental  sensations.  The  loss 
of  green  produces  green-blindness.  All  colours  are 
then  seen  as  combinations  of  red  and  blue ;  the  com- 
position of  the  spectrum  colours  would  be  indicated  by 
the  diagram  in  Fig.  98  by  changing  lUJi^  to  *|R.  The  loss 
of  red  produces  red-blindness.  All  objects  are  seen  in 
combinations  of  green  and  blue ;  the  composition  of 
the  spectrum  colours  would  be  indicated  by  the  lines 
in  Fig.  99  with  (5  instead  of  Xl<2l-  In  blue-blindness 
all  objects  are  seen  in  combinations  of  red  and  green  ; 
the  composition  of  the  spectrum  colours  would  be  in- 
dicated by  the  line  in  Fig.  97  with  JS  omitted.  To  the 
green-blind  person  the  strawberry  and  its  leaves  arQ 


Colour  Sensitiveness  135 

red  ;  to  the  red-blind  they  are  green  ;  to  the  blue-blind 
they  are  red  and  green. 

The  persons  usually  designated  as  colour  blind 
(green  blind  and  red  blind)  are  really  dichromats  of  the 
first  and  second  classes ;  the  cases  of  real  green-blind- 
ness, red-blindness,  and  blue-blindness,  are  rare. 

.The  monochromat  sees  everything  in  light  and 
shade,  presumably  grey.  His  world  is  to  the  world  of 
most  people  what  a  photograph  or  an  engraving  is  to 
the  colouring  of  nature.     These  persons  are  quite  rare. 

One  case  is  related  of  an  architect's  assistant  who  did 
not  understand  in  the  least  what  was  meant  by  colour; 
he  said  that  the  colours  appeared  to  him  as  simply 
shades  of  white  and  black.  He  had  to  use  colours  in  pre- 
})aring  the  plans  of 
buildings  but  was 
guided  by  the  name 
on  the  paint.  One 
of  the  clerks  once 
purposely    scraped 

Oflf    the    names    and  Fig.    ICXX-Monochromats.    Proportion   of  the 

Fundamental  Colour  in  the  Spectrum 

he  used  the  colours  colours, 

wrongly.  A  friend  of  his  had  a  house  with  dark  oaken 
timbers  and  orange  plaster.  He  asked,  when  looking 
at  the  house,  why  the  plaster  was  so  much  darker 
than  the  wood.  His  friend  told  him  that  the  plaster 
was  very  much  lighter  than  the  wood,  but  he  refused 
to  believe  it.  In  a  photograph  which  was  afterwards 
taken  the  plaster  came  out  much  darker  than  the 
oaken  timbers. 

An  idea  of  how  the  world  appears  to  persons  with 
various  forms  of  colour  vision  may  be  obtained  by 


13^         Thinking,  Feeling,  Doing 

considering  how  the  American  flag  appears  to  them ; 
this  is  indicated  in  the  following  table: 

Trichromats  :       red  and  white  stripes  ;  white  stars  on  blue  field 
Dichromats  I :      dark  yellow  and  white 

stripes ;  "         *'       "      "       " 
Dichromats  II :    black  and  white  stripes ;       '■*         ''      "'      "       "■ 

Green-Blind :         red  and  purple  stripes ;  purple  "       "      "       " 
Red-Blind  :            black  and  greenish  blue 

stripes  ;  greenish  blue  stars  on  blue  field 

Blue-Blind  :           red  and  yellow  stripes ;  yellow  stars  on  black  field 

Monochromats :    black  and  white  stripes  ;  white      "      "■  grey      " 

Owing  to  their  inability  to  distinguish  red  and  green 
except  as  different  degrees  of  yellow,  the  dichromats 
cannot  be  safely  employed  in  many  positions  on  rail- 
ways and  on  shipboard.  A  red  signal  is  generally  used 
to  mean  "danger,"  green  to  mean  "all  right"  (or 
"caution"  in  some  cases)  on  the  railway.  On  the 
water  a  red  light  is  on  the  port  side  of  the  boat,  a 
green  one  on  starboard  side;  a  pilot  knows  which 
way  a  vessel  is  sailing  by  seeing  red  or  green. 

The  steamship  Isaac  Bell  collided  with  the  tugboat 
Lumberman  near  Norfolk,  Virginia ;  ten  lives  were 
lost.  The  pilot  of  the  Lumberman  was  afterwards  ex- 
amined and  found  to  be  colour  blind ;  there  was  a  rumour 
that  the  other  pilot  was  also  colour-blind. 

The  pilot  of  the  steamer  City  of  Austria^  which  was 
lost  in  the  harbour  of  Fernandina,  Florida,  was  proved  to 
be  colour  blind.  He  mistook  the  buoys,  and  his  mistake 
cost  the  owners  $200,000. 

Captain  Coburn  reports  :  "The  steamer  Neera  was  on 
a  voyage  from  Liverpool  to  Alexandria.  One  night 
shortly  after  passing  Gibraltar,  at  about  10:30  P.  M.,  I 
went   on  the   bridge,   which  was   then  in   charge   of 


Colour  Sensitiveness  137 

the  third  officer,  and  competent  in  every  way.  I 
walked  up  and  down  the  bridge  until  about  11  p.  m  ., 
when  the  third  officer  and  I  almost  simultaneously 
saw  a  light  about  two  points  on  the  starboard  bow.  I 
at  once  saw  it  was  a  green  light,  and  knew  that  no 
action  was  called  for.  To  my  surprise  the  third  officer 
called  out  to  the  man  at  the  wheel,  'Port,'  which  he 
was  about  to  do,  when  I  countermanded  the  order,  and 
told  him  to  steady  his  helm,  which  he  did,  and  we 
passed  the  other  steamer  safely  about  half  a  mile  apart 
I  at  once  asked  the  third  officer  why  he  had  ported 
his  helm  to  a  green  light  on  the  starboard  bow  ;  but  he 
insisted  it  was  a  red  light  wdiich  he  had  first  seen.  I  tried 
him  repeatedly  after  this,  and  although  he  sometimes 
gave  a  correct  description  of  the  colour  of  the  light,  he 
was  often  incorrect,  and  it  was  evidently  all  guess- 
work." 

A  similar  account  is  given  by  Capt.  Heasley,  of  Liver- 
pool: "After  passing  through  the  Straits  of  Gibraltar, 
thesecond  officer,  who  had  charge  of  the  deck,  gave  the 
order  to  port — much  to  my  astonishment,  for  the  lights 
to  be  seen  about  a  point  on  the  starboard  bow  were  a 
masthead  and  green  light;  but  he  maintained  that  it 
was  a  masthead  and  red,  and  not  until  both  ships  were 
nearly  abreast  would  he  acknowledge  his  mistake.  I 
may  add  that  during  the  rest  of  the  voyage  I  never 
saw  him  makinsj  the  same  mistake." 

The  accidents  due  to  colour  blindness  have  been 
made  quite  uncommon  by  tests  of  all  railway  employees 
and  mariners  who  have  to  do  with  signals. 

The  test  employed  in  most  countries  is  that  of  sorting 
coloured  worsteds  according    to    likeness,     A    light 


138        Thinking,  Feeling,  Doing 

green  skein  is  laid  down  and  the  person  is  told  to 
pick  out  of  a  miscellaneous  heap  "  all  the  colours  like 
it."  Names  of  colours  are  not  used.  If  he  picks  out 
greys,  brownish  greys,  yellows,  orange,  or  faint  pink, 
he  has  defective  colour  vision.  Then  a  purple  skein  is 
laid  before  him.  If  he  picks  out  grey  or  green,  he  is 
a  dichromat  of  the  first  kind ;  if  blue  or  purple,  of  the 
second  kind.  A  red  skein  is  then  used  ;  light  greens 
and  browns  picked  out  as  like  this  indicate  the 
first  kind  of  dichrornasy  ;  dark  greens  or  dark  browns, 
the  second  kind.  Most  cases  of  defective  vision  are 
detected  by  this  test,  but  it  fails  in  quite  a  number  of 
cases;  moreover  the  task  of  matching  colours  is  so 
unusual  for  most  men  that  some  candidates  fail  from 
nervousness. 

The  well-known  fact  that  many  men  of  defective 
colour  vision  pass  the  worsted  test  may  be  illustrated 
by  a  letter  published  from  an  English  railway  man. 
"  I  have  been  on  the  railway  for  thirty  years  and  I 
can  tell  you  the  card  tests  and  wool  tests  are  not  a 
bit  of  good.  Why,  sir,  I  had  a  mate  that  passed  them 
all,  but  we  had  to  pitch  into  another  train  over  it. 
He  could  n't  tell  a  red  from  a  green  light  at  night  in  a 
bit  of  a  fog." 

The  best  form  of  test  is  one  that  copies  as  closely  as 
possible  the  signal  lights  in  actual  use  under  the 
varying  conditions  of  distance,  dimness,  fog,  etc.  A 
convenient  apparatus  for  this  purpose  is  found  in  the 
colour-sense  tester,  (Fig.  101)  an  arrangement  of  col- 
oured glasses,  like  those  of  the  signals,  seen  through 
various  shades  of  grey  glass  and  in  various  combina- 
tions,    The    jnstrunient  is  placed  before  a  light  and 


Colour  Sensitiveness 


139 


the  person  is  required  t )  call  off  the  names  of  the 
colours  he  sees,  the  colours  being  the  simple  ones,  red, 
green,  blue,  yellow,  etc. 
The  person  who  makes  no 
mistakes  has  a  "  safe"  colour 
vision.  This  instrument 
detects  cases  of  colour- weak- 
ness and  dichromasy  that 
pass  the  Holmgren  test 
One  of  my  students  could 
pass  the  Holmgren  test 
perfectly  and  really  distin- 
guish the  colours,  yet  he 
could  not  tell  the  differ- 
ence between  a  red  and  a 
green  light  on  a  car  more 
than  two  blocks  away. 
Another  student,  who  was 
known  to  be  a  dichromat, 
could  not  be  caught  by 
the  Holmgren  test.  Both 
these  cases,  as  well  as  oth- 
ers, revealed  themselves  at 
once  w^th  the  tester. 

The  foregoing  are  the  typ- 
ical forms  of  colour  vision. 
A  considerable  number  of 
trichromats  have  a  green 
sensation  rather  different  from  that  of  the  majority ; 
the  colours  of  nature  appear  slightly  different  to  the 
two  classes.  In  getting  the  grey  equation  (Fig.  96) 
in   a  dark  rooni   illuminated  only   by  sodium   light 


Fig.  101. — Colour-sense  Tester. 


I40       Thinking,  Feeling,  Doing 

(orange-yellow)  I  find  5  to  10  per  cent,  of  my  students  to 
differ  from  the  rest  in  the  results.  There  are  also 
forms  of  colour  vision  in  whicli  the  red  or  the  green 
sensation  is  weaker  than  usual ;  these  may  be  said  to 
be  "colour  weak."  One  of  my  students  showed  no 
defect  in  judging  colours  near  by,  but  could  not  tell 
red  from  green  at  a  distance.  Such  persons  pass  the 
wool  test  perfectly  but  are  caught  by  the  colour  sense 
tester. 

It  is,  of  course,  absolutely  impossible  for  a  colour 
blind  person  to  obtain  any  idea  how  the  world  looks 
to  other  people.  Everything  appears  to  a  dichromat 
as  some  variety  of  yellow,  white,  blue,  and  black; 
what  red,  orange,  and  purple  are  he  cannot  even 
imagine.  Most  such  people  become  aware  tliat  they 
have  a  colour  defect,  but  some  will  insist  that  it  is 
simply  due  to  lack  of  training  in  colours.  One  school 
superintendent  maintained  obstinately  that  two  skeins 
of  wool  that  he  had  classed  alike  were  really  some- 
what different  and  tluit  the  fact  that  I  thought  them 
very  different  was  due  to  a  better  training.  To  my 
eye,  however,  one  skein  was  grey  and  the  other  green  ; 
to  his  they  must  have  both  been  greyish  tints  of  yellow. 

Colour  blindness  is  nearly  always  a  defect  of  birth  ; 
it  can  never  be  remedied.  About  four  in  a  hundred 
men  are  colour  blind,  but  only  about  one  in  five  hundred 
women.  This  has  nothing  to  do  with  education  in 
colours ;  it  is  simply  a  fact  of  sex. 

Colour  blindness  is  hereditary,  passing  along  both 
lines  but  showing  itself  only  in  the  males.  Among 
the  Quakers,  the  proportion  of  colour  blind  persons  has 
long  been   about   one-half  greater  than  among  other 


Colour  Sensitiveness  141 

people.  Nearly  every  Quaker  is  descended  on  botli 
sides  solely  from  a  group  of  men  and  women  who 
separated  themselves  from  the  rest  of  the  world  five 
or  six  generations  ago.  One  of  their  strongest  opinions 
is  that  the  fine  arts  are  worldl}^  snares;  their  most 
conspicuous  practice  is  to  dress  in  drabs.  It  is  possible 
that  many  of  the  founders  of  Quakerism  happened  to 
be  colour  blind ;  it  is  more  probable  that  the  doctrines 
directed  aorainst  briofht  colours  and  works  of  art  would 
repel  persons  of  normal  vision  and  attract  the  colour 
blind  proselytes.  In  fact,  the  enthusiasm  of  most  people 
for  paintings,  stained-glass  windows,  bright  decorations, 
and  the  like,  must  appear  utterly  unreasonable  to  the 
colour  blind.  Tiie  productions  of  many  of  our  artists 
must  appear  actually  hideous  to  the  colour  blind  persons 
who  cannot  tell  the  difference  in  colour  between  a  straw- 
berry and  its  leaves.  Such  people  would  be  likely  to 
join  a  sect  maintaining  the  doctrine  that  such  things 
are  wasteful  or  sinful.  Again,  the  desertions  from 
Quakerism  would  naturally  be  of  persons  in  whom 
natural  instincts  and  abilities  were  stronger.  Dalton, 
the  discoverer  of  colour  blindness,  was  a  colour  blind 
Quaker.  It  is  said  that  he  consented  to  receive  an 
Oxford  degree  only  when  he  was  assured  that  the 
bright  scarlet  hood  that  he  would  have  to  wear  would 
be  replaced  by  a  sombre  one.  It  is  related  of  a  pro- 
minent Quaker  that  he  returned  from  town  one  day 
with  a  bright  red  tie,  a  perfect  abomination  to  his 
family.  It  spite  of  the  trouble  aroused,  it  was  not  a 
case  of  heresy  but  merely  of  colour  blindness. 

A  colour,  as  we  see  it,  depends  on  the  colour  of  the 
neighbouring  objects.  If  two  designs  are  executed  in  the 


142        Thinking,  Feeling,  Doing 


same  grey,  they  will  appear  different  if  the  grounds  are 
of  different  colours.  If  the  grounds  are  red  and  yellow 
respectively,  one  ornament  will  appear  somewhat  green 
and  light,  the  other  somewhat  blue  and  dark.  The  ef- 
fect is  increased  by  placing  tissue  paper  over  them.  Yet 
both  greys  are  exactly  alike.  The  colour  of  the  sur- 
rounding ground  affects  the  grey. 

Bits  of  grey  paper  laid  on  coloured  paper  show 
the  same  result.  If  the  coloured  paper  is  tipped  so  that 
the  small  piece  slowly  slides  off,  the  coloured  tinge 
of  the  grey  can  be  seen  to  slip  off  as  the  paper  goes 
over  the  edge. 

This  influence  of  one  colour  over  another  is  called 
"  contrast."  The  effect  of  the  influence  of  a  colour  is  to 
spread  the  complementary  colour  in  its  neighbourhood. 
Place  a  small  piece  of  grey  paper  on  a  piece  of  coloured 
paper.  When  a  piece  of  tissue  paper  is  laid  over  the 
whole,  the  grey  paper  appears  distinctly  coloured.   The 

tissue  paper  is  used  to  whiten 
the  colours,  the  result  being 
greatest  with  whitish  colours.' 
Disks  to  illustrate  contrast  can 
be  prepared  as  in  Fig.  102,  where 
the  lined  portion  is  to  be  col- 
oured. When  such  a  disk  is 
spun,  the  ring  formed  by  the 
mixture  of  the  black  and  white 
should  be  grey;  itis,however,the 
colour  complementary  to  the  colour  on  the  other  portion. 

'When  two  small  bits  of  grey  paper  are  laid  on  the  two 
colours  in  the  frontispiece  and  covered  with  tissue  paper,  they 
will  appear  tinged  with  purplish  pink  and  pale  blue. 


Fig.  102.— Disk  to  Ulustrate 
the  Effect  of  Contrast. 


Colour  Sensitiveness  143 

Plain  red,  purple,  and  blue  woven  cloths  were  on 
one  occasion  given  to  manufacturers  for  ornamenta- 
tion with  black  patterns.  When  the  goods  were  re- 
turned, the  complaint  was  made  that  the  patterns 
were  not  bhick  ;  those  on  the  red  were  decidedly 
greenish,  those  on  the  violet  were  dark  greenish  yellow, 
and  those  on  the  blue  were  copper-coloured.  By 
covering  the  cloth  in  such  a  way  as  to  expose  only  the 
patterns  without  the  colours,  they  were  seen  to  be  truly 
black.     It  was  an  effect  of  contrast. 

The  colours  that  we  see  are  not  constant ;  they  vary 
through  fatigue.  Look  steadily  at  any  coloured  sur- 
face, for  example,  the  last  figure  in  the  Frontispiece, 
for  a  while ;  then  rest  your  eyes  by  winking  ;  on  opening 
the  eyes  you  will  notice  that  the  colour  seems  brighter. 

Now    look   steadily   at   the   adjacent  black   square 
(Fig.  108)  with  white  circle  for  twenty  seconds;  then 
look  at  a  plain  white  surface.    You  will  see  a  square  of 
brighter  white  while   the   circle   will 
appear  like  the  white  of   the  paper. 
The  white  around  the  original  square 
and   the  circle  had  fatigued  the  eye 
while    the  black  portions  had  rested 
it:  on  looking  at    plain  white  paper    fig.  m-Figure 
the  whiteness   was  brighter  over  the        ^Tmagll^^' 
unfatigued  part ;  therefore  the  square 
appeared  whiter  than  the  rest  of  the  field  of  vision. 

Look  steadily  at  the  last  figure  in  the  Frontispiece 
for  twenty  seconds ;  and  then  at  a  plain  white  surface 
You  will  see  a  purplish  pink  oblong.  Why?  The 
green  oblong  had  fatigued  the  eye  for  that  colour. 
When  the  eye  looks  at  a  white  surface,  it  is  not  equally 


144         Thinking,  Feeling,  Doing 

sensitive  to  the  red,  green  and  blue  that  compose  white ; 
removing  the  green  leaves  red  and  blue,  and  these 
combined  produce  purple.  On  the  oblong  you  will 
see  two  pale  blue  stars.  Why?  Since  the  green  was 
not  very  bright  it  did  not  entirely  fatigue  the  eye  for 
that  colour  and  so  some  of  the  green  light  from  the 
white  paper  had  an  effect;  this  mixed  with  the  purple 
})roduced  purplish  pink.  Experimenting  with  red, 
yellow,  blue  and  purple  in  a  similar  way  you  will  see 
their  "after  images,"  which  are  bluish  green,  blue, 
yellow  and  green  respectively.  The  "  after  images  " 
have,  therefore,  colours  complementary  to  the  originals. 


CHAPTER    XIY 

SEEING   WITH   ONE   EYE 

LET  US  look  at  the  world  with  only  one  eye.  What 
we  see  consists  of  patches  of  colour  arranged 
in  wonderfully  complicated  forms.  It  is  our  duty  to 
determine  some  of  the  laws  of  this  arrangement 

The  first  fact  that  strikes  us  is  that  we  are  looking 
at  some  particular  point  This  is  the  "  point  of  re- 
gard." In  looking  at  this  dot  #  your  point  of  re-gard 
is  the  dot  As  you  read  onward,  your  point  of  regard 
changes  from  one  letter  to  another.  If  you  look  at  a 
person  on  the  street,  the  point  of  regard  is  that  person. 

Keeping  the  eye  steadily  looking  at  the  dot,  notice 
that  you  can  read  the  words  close  around  it  although 
they  are  somewhat  blurred,  and  that,  although  you 
can  see  over  a  whole  region,  including  the  page  and 
part  of  the  room,  all  this  region  is  quite  indistinct 
The  fairly  clear  part  around  the  point  of  regard  is  the 
region  of  distinct  vision ;  the  blurred  part  is  the 
region  of  indistinct  vision.  The  whole  region  seen  is 
called  the  field  of  vision. 

The  boundaries  of  the  field  of  vision  are  determined 
by  moving  objects  from  outside  the  field  toward  it 
till  they  are  seen,  and  by  moving  them  from  the  centre 
outward  till  they  disappear.  The  subject  of  the  experi- 
ment is  seated  in  a  chair ;  one  eye  is  closed;  the  other 
xo  145 


146        Thinking,  Feeling,  Doing 


looks,  without  moving,  straight  ahead  at  a  spot  The 
experimenter  places  a  small  piece  of  white  paper  on 
the  end  of  a  knitting-needle  or  a  stick,  and  starting 
behind  the  subject,  slowly  pushes  it  forward  at  about 
one  foot  from  his  head  till  he  catches  sight  of  it.  The 
paper  is  then  started  where  it  is  seen  and  is  drawn  back 
till  it  disappears.  This  marks  the  limit  of  vision  in 
that  direction. 

The  limits  of  the  field  of  vision  are  determined  and 

recorded  rapidly  by 
means  of  perime- 
ters. One  form  is 
that  shown  in  Fig. 
104  The  small 
piece  of  paper  is 
moved  out  along 
the  curved  arm  in 
one  direction  till 
the  limit  is  found. 
The  arm  is  placed 
in  various  positions 
and  the  experiment 
is    repeated.      The 

Fig.  104.— Perimeter   for  Measuring  the  Field    T^^I^DCr   OI    degrees 

^^^^^^^°^-  is    read    off     each 

time  and  is  marked  on  a  chart.  A  line  drawn  through 
these  points  indicates  the  boundary  of  the  field  of  vis- 
ion. An  average  eye  will  have  a  field  extending  out- 
ward (^.  e.,  away  from  the  nose)  about  85°,  inward  75°, 
upward  73°,  downward  78°. 

If  the  experiments  on  perimetry  are  made  with  col- 
oured objects,  it  will  be  found  that  in  a  narrow  region 


Seeing  with  One  Eye 


147 


along  tlie  edge  of  the  field  of  vision  the  person  will  see 
the  object  without  seeing  its  colour.  In  fact,  in  this 
region  we  are  all  totally  colour  blind ;  we  see  every- 
thing in  an  indefinite  grey  colour. 

Inside  this  one-coloured  border  the  object  takes  on 
a  colour,  but  the  colour  is  seldom  the  same  as  that 
which  it  has  when  seen  directly.     The  limits  at  which 


Fig,  105. — Perimeter  Chart.     Limits  beyond  which  the  Colours  Disappear: 
1,  Violet ;  2,  Yellow  ;  3,  Green  ;  4,  Red  ;  5,  Orange  ;  6,  Blue. 

objects  of  various  colours  lose  their  "  true "  colours, 
i.  e.,  the  colours  when  directly  seen,  are  indicated  for  a 
typical  person  in  Fig.  105. 

Curiously  enough,  the  field  of  vision  with  children 
is  apparently  not  so  great  as  with  adults.  They  can- 
not see  over  so  much  for  any  position  of  the  eye.  The 
reason  probably  is  that  they  are  incapable  of  attending 


14^        Thinking,  Feeling,  Doing 

to  tlie  outer  regions ;  they  confine  thenaselves  to  the 
region  near  the  point  of  regard. 

In  the  field  of  vision  tliere  is  one  place  at  which 
nothing  is  seen ;  this  is  called  the  blind-spot. 

With  the  left  eye  shut,  hold  the  book  at  arm's  length 
and  look  with  the  right  eye  at  the  cross  in  Fig.  106 
The  letters  are  also  seen  indirectly.  Bring  the  book 
slowly  toward  you,  keeping  the  eye  fixed  on  the  cross. 
At  about  a  foot  from  the  eye  the  B   will  disappear 

+  A      0      B 

Fig.  106.—  Diagram  for  Finding  the  Blind-spot. 

entirely.  If  the  book  is  brought  still  closer,  the  B  will 
reappear,  but  the  O  will  disappear,  leaving  a  blank 
space  between  A  and  B.  To  try  the  left  eye  hold  the 
book  upside  down.  There  is  therefore  one  portion  of 
the  field  of  vision  on  which  you  are  absolutely  blind. 
This  is  called  the  blind-spot. 

Althouofh  man  and  his  animal  ancestors  have  alwavs 
had  blind-spots  as  long  as  they  have  had  eyes,  these 
spots  were  not  discovered  till  about  two  hundred  years 
ago,  when  Mariotte  caused  a  great  sensation  by  show- 
ing people  at  the  English  court  how  to  make  royalty 
entirely  disappear. 

The  blind-spot  can  be  drawn  directly  on  paper  by 
keeping  the  eye  fixed  on  the  cross  while  a  pencil  is 
moved  from  where  it  cannot  be  seen  outward  till  its 
point  is  just  seen.  In  this  way  a  dotted  boundary  line 
for  the  spot  is  obtained.  The  blind-spot  lies  to  the 
temporal  side  (opposite  the  nose)  of  the  point  we  are 


Seeing  with  One  Eye 


149 


looking  at  It  corresponds  to  the  place  where  the  optic 
nerve  enters  the  eye.  It  covers  a  region  equal  to  the 
face  of  a  man  seven  feet  distant,  or  eleven  times  the 
size  of  the  full  moon. 

What  do  you  see  at  the  blind-spot?  Everythino- 
disappears  that  is  put  in  the  region  covered  by  it. 
Yet  there  must  be  something  there ;  for,  if  the  O  in 
Fig.  106  be  made  to  disappear,  the  letters  A  and  B  are 
no  nearer  together  than  when  the  O  is  seen.  The  blind- 
spot  must  be  seen  as  white,  for  the  whole  region  appears 
unbroken.  Yet  if  this  experiment  is  made  on  coloured 
paper  the  whole  region  is  of  tlie  same  colour.  Papers 
or  cards  of  various  colours  can  be  readily  prepared  to 
illustrate  this.  We  are  thus  forced  to  the  conclusion 
that  although  we  are  blind  over  this  region,  we  fill  out 
the  lacking  space  by  an  unconscious  act  and  that  it  is 
filled  out  in  accordance  with  the  surroundino^  region. 

Let  us,  however,  try  to  puzzle  the  blind-s]X)t.  A 
card  is  prepared  with  a  white  circle  on  two  colours  as 
shown  in  Fig.  107.     Let  the  white  circle  fall  on  the 


Fig.  107.— Puttiug  a  White  Circle  on     Fig.  lOS. — The  Circle  is  Replaced  by 
the  Bliud-Spot,  the  Colours. 

blind-spot.     The  card  will  appear  as  in  Fig.  108  (see 
Frontispiece).'     Try  a  card  coloured  as  in  Fig.  109 

'  The  coloured  diagram  for  Fig.  107  is  given  as  Fig.  A.  of  the 
Frontispiece.    Hold  the  book  lengthwise  about  a  foot  from  the 


150  Thinking,  Feeling,  Doing 


Fig.  109.— What  Will  Happen 
Now  ? 


If  the  circle  falls  on  the  blind-spot  it  will  be  filled  out 
as  in  Fig.  110. 

Now  trv  a  card  like  Fig.  Ill,  with  the  two  bands  in 
different  colours.  At  last  the  spot  is  puzzled.  One 
moment  the  horizontal  band  will  run  across  the  vertical 
one;  at  another  the  vertical  will  run  across  the  horizon- 
tal. Sometimes  after  many  trials 
the  spot  seems  to  despair  and  the 
person  owning  it  declares  that  he 
really  sees  nothing  there. 

In  looking  at  a  printed  page 
^the  portion  that  falls  on  the 
blind-spot  appears  to  be  printed 
with  indistinct  letters,  as  though 
it  were  pretending  to  read. 

It  is  noteworthy  that  the  space 
around  the  blind-spot  is  not  con- 
tracted. If  the  circle  in  Fig.  107 
falls  on  the  blind-spot, the  sides  of 
the  figure  are  no  nearer  together, 
although  quite  a  space  has  apparently  b^en  removed. 

face.  Close  the  right  eye.  Look  steadily  at  the  +  on  the  right 
hand  side  of  the  page.  Bring  the  book  slowly  nearer  till  the 
letter  A  disappears.  Then  move  the  book  slowly  nearer  or 
further  till  the  entire  white  circle  disappears.  It  will  be  replaced 
by  orange  and  green  as  indicated  in  Fig.  108.  Holding  the 
book  in  the  same  way,  close  the  left  eye  and  look  steadily  at 
the  -f  on  the  left.  Move  the  book  until  the  circle  around  the 
letter  B  disappears.  The  result  will  be  as  indicated  in  Fig.  110. 
The  coloured  diagram  for  Fig.  Ill  forms  the  middle  of  the 
Frontispiece.  With  the  left  eye  closed  C  is  observed ;  with 
the  right  closed,  C".  The  book  is  brought  near  until  the  middle 
of  the  cross  disappears.  The  diagrams  appear  blurred  because 
they  must  be  held  so  near  the  eye  on  account  of  their  smallness. 


Fig.  110.— The  Result. 


Fig.    111.   A  Puzzler  for  the 


Seeing  with  One  Eye  151 

The  last  figure  in  the  Frontispiece  shows  an  inter- 
esting illusion.  When  we  look  with  one  eye — or 
witli  both  eyes — steadily  at  the 
white  dot  D,  we  see  the  orange 
stars  at  first  but  finally  one 
disappears  and  is  replaced  by 
the  green  of  the  field.  Some- 
times both  disappear.  The  "'"'  '''BUud-spot' 
star  returns  again  for  a  while  and  then  dis- 
appears. This  is  repeated  as  long  as  tlie  figure 
is  observed.  The  disappearance  may  not  be  apparent 
at  first  to  the  observer  because  he  finds  difficulty  in 
looking  steadily  at  D  while  watching  the  stars.  He 
should  stare  as  in  reverie,  and  repeat  the  experiment 
a  number  of  times.  My  explanation  of  the  phenomenon 
is  that  the  orange  stripe  fatigues  the  eye,  producing  a 
temporary  blind-spot,  which  is  filled  according  to  the 
usual  principle. 

We  notice  that  what  we  see  with  one  eye  "occupies 
space."     Let  us  notice  some  of  the  peculiarities  of  this 
"  monocular  space."  ' 

Put  a  blank  sheet  of  paper  on  a  board  and  place  a  dot 
in  the  middle.  Holding  it  directly  in  front  of  the  eye 
so  that  the  dot  is  at  the  point  of  regard  looking  straight 
forward,  draw  four  apparently  equal  lines,  as  indicated 
in  Fig.  112.  On  measuring  them  the  vertical  one 
above  the  dot  will  be  found  shorter  than  the  vertical  one 
below.  Both  will  be  shorter  than  the  horizontal  lines  ; 
the  horizontal  lines  will  generally  be  equal.     We  can 

'  More  extended  treatment  of  the  facts  of  monocular  and  bin- 
ocular space  is  to  be  found  in  the  various  books  on  psychology  ; 
I  have  given  special  attention  to  them  in  my  New  Psychology. 


152         Thinking,  Feeling,  Doing 


A 


thus  conclude  tliat  space  above  the  point  of  regard 
is  overestimated  as  compared  with  space  below ;  that 
space  in  the  vertical  direction  is  overestimated  as  com- 
pared with  horizontal  space ;  and  that  horizontal  space 
inward  or  outward  is  about  the  same.  This  explains 
why  c  and  not  h  seems  the  continuation  of  a  in  Fig.  113. 
Placing  a  dot  on  the  paper  in  the  same  way,  draw  a 
square  around  it.    By  turning  the  square  sidewise  you 

will  see  that  you 
have  really  made 
it  too  short.  Turn 
this  book  upside 
down.       What    do 

^^  you  notice  in  regard 

to  the  letter  s  and 

the  figure  8?  Why 

are  they  made  so  ? 

When  the  point 

Fig.  112.— What  the  Eye  Considers  to  be  Equal  of       regard      mOVCS 
Distances.  i      •■      i 

upward  it  has  a 
tendency  to  move  outward  ;  when  it  moves  downward, 
it  moves  also  inward.  Look- 
ing at  the  edge  of  the  room, 
you  will  notice  as  you  look 
rapidly  along  it  toward  the 
ceiling  that  the  whole  edge 
seems  to  tip  sidewise.  With 
the  right  eye  it  tips  toward  the 
left,  with  the  left  eye  toward 

the  right  As  you  look  rap-  ^'^-^au^^f'SVnvhj^r*'""' 
idly  downward  toward  the  floor,  the  edge  appears  to 
tip  in  the  opposite  direction.     This  tipping  is  very  dis- 


V 


\ 


Seeing  with  One  Eye  153 


agreeable  in  the  cities  of  tall  buildings.    If  you  bappen 
to  look  at  them  from  one  side  of  the  eye,  they  seem  to 


B 


0 


Fig.  114.— Illusion  of  the  Interrupted  Distance. 


be  leaning  dangerously  over  the  street ;  if  from  the  other, 
they  seem  to  slant  back  as  if  disdaining  the  streets 
below  them.  The  amount  of  this  tipping  in  the 
eye  can  be  measured.  Eule  a  horizontal  line  on  a 
sheet  of  paper;  then  lay  the  edge  of  the  raler  across  it 
at  what  you  judge  with  one  eye  to  be  a  right  angle 


ABC 

Fig.  115.— The  Distorted  Squares. 

and  draw  the  line.  On  another  sheet  of  paper  do  the 
same  for  the  other  eye.  Your  two  right  angles  will 
disagree  to  a  small  extent 

Distances  are  judged  by  the  difficulty  in  traversing 
them;  if  the  road  is  hard,  or 
if  you  make  many  stops  by 
the  way,    it   is  much    longer 
than  otherwise.     The  distance 
between  the  two  dots  A  and 
B  in   Fig.    114  is  apparently 
greater  than  that  between  B   fig.  iie.-The  Enlarged  Angle. 
and  C.     The  intervening  dots  are  like  tempting  seats 
by  the  wayside.    The  journey  is  really  made  harder 


154        Thinking,  Feeling,  Doing 

and  apparently  longer  because  your  attention  is  caught 
at  each  one.  For  the  same  reason  the  square  A  in  Fig. 
115  appears  too  long  and  B  appears  too  tall.  Fig.  116 
shows  the  same  illusion  for  angles. 


Fig.  117.— niusion  of  Filled  Space. 

It  is  evident  from  these  facts  why  women  like  to 
have  as  many  bows,  ribbons,  buttons,  etc.,  as  possible 
on  the  dress.     The  more  the  surface  of  the  dress  is 

broken  up,  the  taller  the 
person.  The  illusion  is 
heightened  by  the  diver- 

sity  of  colours  employed. 

The    open   distance    in 
Fig.  117  is  apparently  less 

Fig.  118.— Displacement  by  Inclined     than  the  line-distanCC.       It 

is  harder  to  walk  on  a 
straight  and  narrow  path  than  to  go  as  you  please; 
you  may  go  perfectly  straight  anyway,  but  with  no 
directing  line  you  are  free  from  constraint. 

In  viewing  two  lines  meeting  at  an  angle,  the  smaller 
angle  is  overestimated  as  compared  with  the  larger.  The 
effect  is  to  press  the  sides  of  the  smaller  angle  outward. 
It  is  a  general  law  of  mental  life  that  small  things  are 
thought  greater  than  they  are  in  comparison  with 
large  ones.  The  two  horizontal  lines  in  Fig.  118  do 
not  seem  to  be  parts  of  the  same  straight  line  because 
the  acute  angles  are  overestimated  and  the  lines  are 
apparently   bent   from   the    horizontal.      A    striking 


Seeing  with  One  Eye 


155 


method  of  showing  this  illusion  is  to  draw  a  horizontal 
line  on  a  slate  and  then  after  drawing  two  inclined 


Fig.  119. — Breaking  Parallel  Lines. 

lines,  as  in  the  figure,  to  erase  the  middle  portion.  In 
spite  of  the  fact  that  the  two  horizontal  lines  are  known 
to  belong  to  the   same  straight  line   the  illusion   is 


Fig.  120.— Tipping  Parallel  Lines. 

irresistible.     This  tipping  of  a  line  in  the  direction  in 
which   an   acute   angle  points  is  intensified  when    a 


156        Thinking,  Feeling,  Doing 


number  of  angles  are  made,  as  in  Fig.  119.     The  top 
line,  for  example,  has  acute  angles  above  it  wliicli  tip 


^==^=§^\\\i//^^m^ 

^^^^' 

^^^^// 

\\^^^^^$ 

tI 


Fig.  121.— Bending  Straight  Lines. 

it   downward  toward   tlie  ends.     Tlie  second  line  is 

a  affected  in  the  opposite  way. 
The  horizontal  lines  are 
really  parallel.  See  also 
Fig.  120.  A  continually 
increasing  change  of  direc- 
^,  tion  is  shown  in  Fig.  121. 
tionofa?    Why?  rji|^^    ^^^    horizontal    lines 

appear  curved.     The  illusions  in  Figs.  122,  123,  and 


i-^ 


Fig.  122  —Which  is  the  Continua- 


^v 


^ 


\ 


Fig.  123.— Continu- 
ation of  a  seems 
to  be  c.     Why  ? 


\, 


Fig.  124.— Why  ? 


124  arise  from  the  same  phenomenon  combined  with 


that  illustrated  in  Fig.  113. 


Seeing  with  One  Eye 


157 


/K 


N/ 


All  the  illusions  from  Fig.  ll-i  to  Fig.  124  can  be 
explained  b}^  the  law  that  the  apparent  size  of  an  object 
depends  on  the  amount  of  attention  it  receives.  The 
interrupted  distance  receives  more  attention  and  is 
therefore  mentally  greater.  An  angle  in- 
cludes a  space  and  two  inclosing  lines; 
diininishing  the  amount  of  space  does 
not  diminish  the  amount  of  attention 
required  for  the  inclosing  lines. 

There  is  still  another  class  of  illusions 
resting  on  a  mistake  of  attention. 
The  vertical  lines  in  Fig.  125  are 
all  of  the  same  length,  although  appar- 
ently quite  different.  The  reason  for 
this  illusion  appears  most  clearly  in  the 
coin  illusion  (Fig.  126).  For  this  illusion 
a  person  is  required  to  place  three  coins 
in  such  a  way  that  the  distance  between 
the  left  hand  edge  of  one  end  coin  and 
the  rio:ht  hand  edoe  of  the  middle  coin 
is  the  same  as  between  the  right  hand 
edge  of  the  middle  coin  and  the  left  hand 
edge  of  the  other  end  coin ;  in  other 
words  the  distance  between  the  opposite 
sides  of  the  two  left  hand  coins  is  the 
same  as  the  distance  between  the  ad- 
jacent sides  of  the  middle  and  right  hand  coins.  The 
arrangement  in  Fig.  126  appears  about  correct,  but 
measurement  shows  4'"^  (If  inches)  for  the  distance 
that  includes  the  coins  and  2yV""  (1  inch)  for  the  empty 
distance.  The  explanation  is  that  although  we  thmk 
we  are  attending  to  points  on  the  edges  of  the  coms, 


V 


A 


Fig. 125.— Changing 
the  Length  of  a 
Line  by  Different 
Cross-lines. 


15^         Thinking,  Feeling,  Doing 

we  are  really  thinking  considerably  of  the  whole  coin  ; 
we  consequently  arrange  the  coins  as  if  we  were  adjust- 
ing for  points  much  inside  of  the  edges.     Likewise  in 


Fig.  126.— The  Coin  Illusion. 

Fig.  125  we  are  really  using  the  areas  inclosed  by  the 
slant  lines  instead  of  the  points  at  the  apexes. 

The  appearance  of  Fig.  127  depends  entirely  upon 
attention.  At  one  moment  it  appears  like  a  stairway, 
at  the  next  like  an  overhanging  cornice.     The  picture 


Fig.  128  —The  Changing  Rings  ; 

Which  is  the  Front  End 

of  the  Rings  '? 


Fig.  127,— An  Overhanging  Cornice 
or  a  Stairway  ? 


is  itself  flat;    the   relief   is   due   to   suggestion.     As 
there  are  two  conflicting  suggestions,  one  or  the  other 


Seeing  with  One  Eye  159 

prevails   accordingly   as   we    attend   to   it.       Similar 
illusions  are  numerous  ;  one  other  is  shown  in  Fig  128. 

Up  to  this  point  nothing  has  been  said  about  the 
depth  or  distance  of  objects.  Is  the  world  of  one  eye  a 
flat  surface  ? 

On  entering  into  a  strange  house  with  one  eye 
bandaged,  it  is  difficult  to  obtain  an  accurate  idea  of 
the  distance  of  objects.  The  whole  place  seems  al- 
most flat.  Looking  out  of  a  window  with  one  eye, 
the  view  appears  almost  as  if  painted  directly  on  the 
window-pane. 

We  know  from  experience  that  objects  decrease  in 
size  as  they  recede.  From  the  rear  platform  of  a  rail- 
way train,  the  houses,  signals,  persons,  tracks,  etc., 
can  actually  be  seen  to  shrink  together.  If  we  know 
the  actual  size  of  an  object  we  can  estimate  the  distance ; 
if  we  know  the  distance  we  can  estimate  the  size. 

In  estimating  the  distance  of  unknown  objects  we 
are  guided  greatly  by  the  view  of  the  ground  in  front 
of  them.  Thus  a  tree  seen  down  the  road  can  be 
roughly  estimated  in  height  because  the  objects  along 
the  road  afford  an  indication  of  the  distance. 

Since  our  opinion  of  the  size  of  an  object  depends  on 
the  apparent  distance,  any  illusions  of  distance  will 
produce  illusions  of  size. 

The  fact  that  subdivided  distance  appears  greater 
than  undivided  distance  was  illustrated  in  Fig.  II4.  In 
looking  toward  the  horizon,  the  glance  meets  innumer- 
able objects  that  break  up  the  space,  whereas  in  look- 
ing directly  upward  we  find  a  perfectly  clear  space. 
Consequently  objects  in  a  horizontal  direction  appear 
more  distant  than  objects  in  a  vertical  direction. 


i6o        Thinking,  Feeling,  Doing 

For  this  reason  the  sky  does  not  appear  like  the 
inner  surface  of  a  ball,  but  like  the  under  side  of  a 
watch-glass.  The  amount  of  this  flattening  is  readily 
determined.     Stars  lying  23^  above  the  horizon  are 


Fig.  129.— Shape  of  the  Sky. 

apparently  half  way  toward  the  top.  In  Fig.  129 
you  are  standing  at  A.  Lines  are  drawn  from  A  at 
an  angle  of  23^  to  the  flat  ground  HH  on  which  you 
stand.  The  sky  must  therefore  appear  of  such  a  shape 
that  a  line  drawn  from  H  to  B  is  half  the  distance  from 


Fig.  130.— The  Moon  Illusion. 

H  to  Z.  Such  a  surface  is  indicated  by  the  curved 
line. 

Owing  to  the  apparent  shape  of  the  sky,  the  moon 
appears  to  be  much  further  away  when  it  rises  than  it 
does  when  it  is  overhead  with  nothins^  between.  The 
moon  is  seen  by  the  eye  as  the  same  in  both  cases,  but 
the  moon  near  the  horizon  is  apparently  larger  because 
it  seems  further  away. 

Another  means  of  judging  distance  is  found  in 
shades  and  shadows.  With  one  eye  closed  and  with 
the  back  to  the  light,  hold  a  mask,  preferably  painted 


Seeing  with  One  Eye  i6i 

inside,  so  that  the  seeing  eye  looks  directly  into  the 
inside.  If  no  shadows  are  cast,  the  eye  is  unable  to 
tell  whether  it  is  lookinsr  at  the  inside  or  the  outside 
The  nose  will  at  one  moment  appear  to  be  a  hollow  nose 
pointing  away  from  the  observer  and  at  the  next  a  solid 
nose  pointing  toward  him.  But  the  moment  a  shadow 
is  allowed  to  fall  by  a  change  of  light,  the  eye  knows 
at  once  that  the  hollow  side  is  turned  toward  it. 

Another  influence  res^ulatingr  our  estimate  of  dis- 
tance  and  therefore  of  size  is  the  unclearness  of  the 
air.  The  air  nearly  always  contains  a  quantity  of  mist 
which  makes  objects  bluer  and  more  indefinite  as  the 
distance  increases. 

In  perfectly  clear  air,  such  as  is  common  in  the  drj^ 
regions  of  the  Eocky  Mountains  or  in  portions  of 
Maine  and  Canada,  the  distance  of  objects  is  often  quite 
a  puzzle.  A  canoeist  on  a  lake  in  such  an  atmosphere 
cannot  tell  whether  an  island  in  front  of  him  is  one 
mile  or  ten  miles  awa}^ 

The  coast-dweller  is  subject  to  the  opposite  illusion 
in  the  mountains,  and  innumerable  tales  are  told  of 
travellers  who  start  for  a  before-breakfast  walk  to  a 
neighbouring  hill  which  is  really  twenty  miles  away. 

Those  who  have  come  into  a  cloud  while  ascending 
a  mountain  will  remember  that  a  small  wood-pile  looks 
like  a  barn,  a  cow  appears  larger  than  an  elephant, 
men  are  giants,  etc.  Painters  use  "  atmosphere  "  to  show 
the  distance  of  objects  in  a  landscape. 

There  are  also  illusions  of  both  size  and  distance 
due  to  association.  Clocks  and  flags  on  towers  appear 
much  smaller  than  they  really  are,  because  we  are  ac- 
customed to  house  clocks  and  moderately  sized  flags. 


i62        Thinking,  Feeling,  Doing 

The  clock  of  the  Battel!  Chapel  as  seen  from  the  Yale 
campus  at  a  distance  of  two  hundred  feet  appears  about 
two  feet  in  diameter;  its  actual  size  is  ten  feet. 

A  tall  object  casts  a  longer  shadow  tlian  a  shorter 
one.  During  the  greater  part  of  the  day  the  shadows 
cast  by  the  sun  are  of  moderate  size,  but  early  in  the 
morning  or  late  in  the  evening  they  become  enormously 
large.  This  exaggeration  we  cannot  resist,  and  so  at 
those  times  trees  and  houses  appear  much  taller  than 
usual. 

There  is  another  influence  to  which  I  think  no  one 
has  ever  called  attention,  namely,  the  emotion  pro- 
duced by  the  object.  In  dim  light,  as  at  night,  most 
persons  feel  an  indefinite  uneasiness,  which  in  nervous 
persons  and  children  often  actually  amounts  to  fear  and 
terror.  This  uneasiness  and  fear  exaggerates  the  size 
of  the  object.  On  a  dark  night  the  mountains  around 
an  inclosed  lake,  e.  g.,  the  Lake  of  Como,  assume  an 
overwhelming  aspect  and  appear  far  higher  than  in 
broad  daylight  or  in  pleasant  moonlight.  The  stories 
of  frightened  children  are  not  exaggerations,  but  true 
comparisons  of  the  apparent  sizes  of  terrifying  and  non- 
terrifying  objects.  A  similar  reason  may  explain  the 
"snake  stories." 


CHAPTER    XV 


SEEING    WITH    TWO    EYES 


WHEN  the  e^'es  are  opened  and  closed  rapidly 
in  succession,  objects  seem  to  form  different 
pictures  for  the  two  eyes.  When  both  eyes  are  opened, 
a  tliird  view  is  obtained.  The  world  as  seen  with  the 
left  eye  differs  from  the  world  as  seen  with  the  right 
eye  ;  the  world  as  seen  with  both  eyes  is  again  a  differ- 
ent matter. 

In  our  usual  experience  we  see  the  world  as  a  single 
world,  although  we  have  two  eyes  that  see  differently. 
When  we  lose  control  over  our  vision,  as  in  a  state  of 
intoxication,  the  two  eyes  are  liable  to  act  independ- 
ently and  things  are  seen  double. 

The  view  with  the  right  eye  is  what  would  be  seen 
with  the  left  eye  if  it  were  moved  a 
short  distance  to  the  right,  and  like- 
wise the  left  e3'e  sees  what  the  right 
eye  would  see  if  moved  toward  the 
left.  The  pictures  differ  only  in  the 
point  of  view. 

The  view  with  botb  eyes  has  a  re- 
lief, a  rotundity,  that  is  wholly  lack- 
ing in  the  one-eye  views. 

In  lookino;  at  a  book  with  theris-ht 
eye  we  get  the  flat  view  as  in  Fig. 
131 ;    with   the  left  eye  we  get  the  flat  view  as  in 

163 


IW 


^ 

S5S-' 


i:=;- 
::=:. 


Fig.  131. 


Fig.  132. 


164        Thinking,  Feeling,  Doing 


Fig.  132.  But  with  both  eyes  the  book  appears  in 
relief.  We  imagine  we  see  the  book  as  in  Fig.  133. 
What  we  really  see  is  shown  in  Fig.  134. 

This  union  of  two  different  fiat  views  into  a  single 
solid  view  is  the  fundamental  fact  of  two-eyed  seeing, 
or  binocular  vision.  The  union  is  unconsciously  per- 
formed and  is  irresistible.  Let  us  trace  the  process 
step  by  step. 

Holding  the  head  directly  above  these  two  dots,  let 


the  eyes  stare  as  in  reverie,  i.  e.,  looking  far  behind  the 
paper.  Four  dots  will  be  seen,  each  eye  seeing  two  dots. 
If,  however,  you  look  at  some  imaginary  object  not  far 
behind  the  paper,  the  two  middle  dots  wnll  come  to- 
gether. There  will  then  be  three  dots,  the  middle  one 
being  a  combination  of  one  dot  from 
each  eye.  This  can  be  very  plainly 
seen  by  sticking  the  two  dots  on  a 
window-pane  or  a  piece  of  glass ; 
when  you  look  at  some  object  at  a 
proper  distance  beyond  the  glass, 
the  two  middle  dots  fuse  tosrether. 

After  the  union  of  the  two  middle 
pictures  into  one  the  two  outer  ones 
are  still  seen.     To  be  rid  of  these 
Fig.  133.    outsidc  picturcs  all  that  is  needed     Fig.  134. 
is  to  place  a  strip  of  paper  from  the  nose  to  the  middle 
point  between  the  two  dots.     This  makes  it  evident 
that  the  single  dot  seen  is  a  compound  of  the  dot  from 
the  right  eye  with  the  dot  from  the  left. 


Seeing  with  Two  Eyes  165 

Exactly  the  same  fact  is  illustrated  in  Fig.  135  where 
the  prublem  is  to  put  the  bird  in  the  cage.  A  visiting 
card  is  placed  from  the  line  A  to  B  to  the  nose,  the 
eyes  are  relaxed  and  the  bird  goes  into  the  cage  with- 
out difficulty. 

Most  persons  find  it  tiresome  or  difficult  to  observe 
views  in  the  way  just  described.     Tiie  presentation  of 


B 

Fig.  135.— Put  the  Bird  in  the  Cage  by  Binocular  Vision. 

pictures  to  the  eyes  separately  is  most  conveniently 
done  by  the  stereoscope,  of  which  one  kind  is  shown 
in  Fig.  136.  A  card  containing  the  two  pictures  is 
placed  on  the  bottom.  The  left  eye  sees  only  the  left- 
hand  picture,  the  right  eye  only  the  right. 

The  principle  of  the  stereoscope  consists  in  bring- 
ing together  the  middle  pictures  for  each  eye  and  in 
avoiding  the  outer  ones.  This  is  most  commonly 
done  by  means  of  prismatic  lenses. 

The  prism  stereoscope  contains  two  glass  prisms 
71,  p,  with  a  partition  between  and  in  front  of  them. 


1 66        Thinking,  Feeling,  Doing 


Fig. 


c 

136.  — The      Prism 
Stereoscope. 


An  object  which  is  at  m  when  directly  viewed, 
apparently  changes  its  position  to  some  such  place  as  c 
when  seen  through  the  prism.  Two 
prisms  can  be  so  chosen  that  for  the 
left  eye  a  picture  at  m  is  transferred 
to  c  and  for  the  right  eye  a  picture 
at  0  is  transferred  to  the  same  place. 
The  two  impressions  from  different 
eyes  will  then  be  united. 

It  is  desirable  that  the  prisms 
should  at  the  same  time  be  lenses, 
for  the  following  reason.  In  ex- 
perimenting with  the  two  dots  it  will 
have  been  noticed  that  when  the 
gaze  was  directed  to  a  pomt  beyond 
them  they  seemed  blurred  around  the  edges.  There 
are  very  few  people  who  can  make  each  eye  look 
straight  forward  and  yet  see  near  objects  distinctly. 
When  looking  at  distant  objects  their  eyes  are  far- 
sighted  for  near  objects.  As  it  is  necessary  to  have 
the  stereoscopic 
pictures  near  at 
hand  and  yet  have 
the  lines  of  regard 
parallel,  the  far- 
sightedness is  cor- 
rected by  lenses. 
The  two  prisms 
must  thus  also  be 
magnify  i  ng  lenses. 

The     series      of  Fig.  137.— The  Book  stereoscope ;  How  to  Use  it. 

stereoscopic  figures  in  this  chapter  are  ready  for  the 


Seeing  with  Two  Eyes  167 

application  of  the  stereoscope  directly  to  the  book. 
The  simplest  method  is  to  unscrew  the  back  portion  of 
any  stereoscope  and  hold  it  to  the  eyes  directly  before 
the  picture  in  the  book,  as  shown  in  Fig.  137.  An- 
other method  is  to  cut  off  the  end  of  the  stick  of  the 
stereoscope  till  the  book,  when  placed  against  the  end 
is  at  just  the  proper  distance. 

When  two  like  pictures  are  placed  so  that  the  prisms 
cause  them  to  fall  exactly  on  the  same  spot,  the  images 
are  seen  as  one.  There  is  no  effect  of  solidity.  The 
two  heads  in  Fig.  138  appear  as  one  flat  drawing. 

When  the  two  pictures  are  not  alike,  they  make  a 


Fig.  138.— Two  Like  Pictures. 

compound  figure,  as  in  Figs.  139,  140.  When  the  two 
pictures  are  farther  apart  than  the  distance  of  the 
middle  points  of  the  prisms,  they  fall  beside  each 
other.  In  Fig.  141  the  horizontal  projections  are  at 
the  proper  distance  for  union,  whereas  the  vertical  bars 


I  11^ 


Fig.  139.— Unlike  Pictures  to  be  Combined. 


are  too  far  apart.     The  result  is  an   H-     The  outline 
of  the  horizontal  bar  is  darker  because  the  black  line 


i68        Thinking,  Feeling,  Doing 

of  one  picture  falls  on  the  black  line  of  the  other, 
whereas  the  black  line  of  the  vertical  bar  in  one 
picture  falls  on  the  white  space  in  the  other. 

Up  to  this  point  the  results  of  two-eyed  vision  have 


Fig.  140.— Prometheus. 


been  flat  pictures.     The  production  of  the  effect  of  ob- 
jects in  relief  is  not  quite  so  simple. 

Let  two  pencils  be  held  upright  before  the  eyes  in  a 
line  directly  in  front  of  the  nose  and  at  about  four 


1/ — V 


A — 71 


Fig.  141.— The  H. 

inches  apart.  When  looking  at  the  farther  pencil  you 
see  two  nearer  pencils,  as  in  Fig.  142.  The  image  L 
belongs  to  the  left  eye  because  it  disappears  when  that 
eye  is  closed ;  R  belongs  to  the  right  eye.  This  con- 
dition of  the  extra  images  is  called  crossed  disparity; 
it  is  to  be  remembered  that  objects  nearer  than  the 
point  of  regard    are    seen   with  crossed  disparity. 


Seeing  with  Two  Eyes 


169 


A 


h 


On  looking  at  the  nearer  pencil,  the  farther  appears 
double  (Fig.  143).  By  closing  one  eye  it  is  evident 
that  the  farther  pencil  is  seen  with  uncrossed  disparity. 
Thus  when  we  look  at  any 
point,  the  objects  nearer  than 
that  point  are  seen  with 
crossed  disparity,  those  farther 
than  it  w^ith  uncrossed  dis- 
parity. 

Now  hold  a  single  pencil 
with  one  end  pointing  to  the 
nose  about  two  feet  away  and 
the  other  straight  in  front. 
Looking  at  the  farther  end, 
you  would  expect  the  nearer 
one  to  be  seen  as  two  ends 
in  crossed  disparity  (Fig. 
144);  looking  at  the  nearer  end  you  would  expect  to 
see  two  farther  ends  in  uncrossed  disparity  (Fig.  145) ; 
looking  at  the  middle  you  w^ould  expect  to  see  both 
ends  double  in  opposite  w^ays  (Fig.  146).  Since  the 
pencils  are  continuous  to  the  ends,  ^^ou  would  expect 
the  double  vision  to  extend  down  the  point  of  regard. 
Wliat  you  actually  see  is  one  pencil  i?i  relief  (¥\g.  147). 
The  continuity  of  the  object  transforms  the  double 
image  into  a  single  one  with  a  new  property. 

The  fundamental  law  of  binocular  relief  is  this  :  Tico 
different  flat  inciures  of  the  same  object  will  he  combined 
into  a  relief  if  eacli  picture  is  such  as  would  be  seen  by  the 
corresponding  eye  singly. 

If  the  two  pictures  in  Fig.  148  are  seen  with  the 
stereoscope,  the  result  is  a  union  of  the  two  views  into 


Fig.  142.— 

Crossed 

Disparity. 


Fig.  143.— 
Uncrossed 
Disparity. 


I70         Thinking,  Feeling,  Doing 


Fig.  144.— What  we  would  Ex- 
pect when  Looking  at  the 
Farther  End. 


r- 

■^ 

•^       \ 

1 

r<    •.■'. 

^ 

Fig.  145.— What  we  would  Ex- 
pect when  Looking  at  the 
Nearer  End, 


m'  ■ 

s 

f 
i 

^ 

Fig.  146.— What  we  would  Expect 
when  Looking  at  the  Middle. 


Fig.  147.— What  we  Actually  See. 


Fig.  148.— The  Pyramidal  Box. 


Seeing  with  Two  Eyes  171 

one  solid  pyramid  because  the  two  views  are  drawn  as 
such  a  pyramid  would  appear  to  the  eyes  used  singly. 


a 

d 

1 


Q 


If  the  outer  squares  are  drawn  so  as  to  be  seen  in 
crossed  disparity  (as  by  exchanging  the  two  diagrams 
in  Fig.  148),  the  larger  end  of  the  square  is  nearer  than 


172         Thinking,  Feeling,  Doing 

the  smaller  end  and  we  are  apparently  looking  at  the 
pyramid  from  the  bottom. 

It  is  possible  to  tell  beforehand  whether  the  pyramid 
is  seen  from  the  top  or  from  the  bottom.  As  the  small 
squares  are  at  the  regular  distance  apart  the  point  of  re- 
gard is  found  in  the  small  end.     The  large  squares  are 


CO 

% 


S 

cS 
u 

>. 

Oh 


a 

a 

o 
O 

a> 

,£: 
Eh 

I 


too  far  apart  and  are  not  crossed  :  this  end  of  the  pyramid 
must  be  seen  in  uncrossed  disparity.     But  objects  seen 


Seeing  with  Two  Eyes 


173 


3 


in  uncrossed  disparity 
are  farther  away  than 
the  point  of  regard ; 
consequently  the  large 
end  is  farther  away. 
We  are  therefore  look- 
ing at  the  pyramid 
from  the  top. 

These  relations  are 
shown  in  Fig.  149. 
The  outer  circles  for 
each  pair  are  at  the 
proper  distance  apart 
and  unite  to  form  the 
base  at  the  point  of 
regard.  The  smaller 
circles  are  seen  in  dif- 
ferent relations  of  dis- 
parity, with  the  effect 
that  the  pictures  form 
a  series  of  funnels,  the 
bottom  one  being  long 
and  pointed  toward 
the  observer,  the  next 
being  shorter  but  like- 
wise pointed,  the  mid- 
dle one  being  a  flat 
disk,  the  fourth  being 
short  and  pointed 
away,  and  the  top- 
most one  being  long 
and  likewise  pointed. 

From  these  prin- 
ciples it  will  be  easy 


174        Thinking,  Feeling,  Doing 

to    explain     tlie     diagrams     shown     in     Figs.     150- 

153. 

Tlie  stereoscopic  views  of  buildings,  persons,  and 
landscapes,  sucH  as  can  be  obtained  everywhere, 
are  resolvable  into  the  same  principles  aided  by 
the   shading,    shadows,   and   perspective. 

In  addition  to  the  effect  of  relief  which  we  gain 
by  stereoscopic  vision  there  are  several  other  im- 
])ortant  results  of  two-eyed  seeing.  Among  them 
are  -:  (1)  binocular  strife,  (2),  binocular  lustre,  and  (3) 
binocular  contrast. 


Fig.  154.— Binocular  Strife. 

Binocular  strife  is  produced  when  the  two  different 
views  are  separately  presented  to  the  two  eyes.  In 
Fis:.  154 the  various  rino^s  are  filled  with  lines  in  differ- 
ent  directions  ;  what  happens  when  they  are  combined 
with  the  stereoscope?  One  of  the  rings  is  filled  with 
shading  which  slants  in  one  direction  for  the  left  eye 
and  in  the  other  direction  for  the  right  eye.  The 
result  is  peculiar.  Yery  rarely  do  the  two  sets 
of  lines  combine  to  form  crossed  shading.  Sometimes 
the  left-hand  shading  alone  appears,  sometimes  the 
right-hand  shading  wins ;  generally  the  two  alternate 
frequently  and  irregularly.  If  you  happen  to  think  of 
one  kind  of  shading,  that  appears.  But  you  cannot  keep 
either  kind  for  more  than  an  instant;  the  other  will  re- 
place it     It  seems  to  be  largely  a  matter  of  attention. 


Seeing  with  Two  Eyes 


175 


Yet, the  most  frequent  aspect  of  all  is  that  the  shading 
is  in  patches;  the  left-hand  picture  predominates  in 
parts  while  the  right-hand  one  occupies  the  rest.  And 
the  queer  thing  about  it  is 
that  these  parts  are  con- 
tinually changing.  The  in- 
ner circle  behaves  in  the 
same  way.  It  is  in  truth  a 
strife  between  the  two  eyes. 

Binocular  lustre,  or  pol- 
ish, is  so  called  from  the 
resemblance  of  the  effect  to 
actual  polish.  A  polished 
object  contains  a  contra- 
diction in  itself.  Its  little 
marks,  irregularities,  and 
corners  remain  the  same, 
although  changes  in  the 
position  of  the  light  and 
in  the  objects  near  it  are 
followed  by  changes  in  the 
reflection.  A  polished  door- 
knob differs  from  an  un- 
polished one  by  partially 
reflectino;  the  lisrhts  from 
surrounding  objects ;  there 
is  a  strife  between  the 
colour  and  general  appear- 
ance the  knob  would  have 
if  unpolished  and  the  appearance  of  reflection  of 
surrounding  objects. 

In  Fig.  155  the  left  eye  receives  an  impression  of 


1^6         Thinking,  Feeling,  Doing 


a  wliite   crystal  and  the  right  eye   one   of   a   black 
crystal ;  when  viewed   with  a  stereoscope,  the   same 

space  is  covered  by  a 
different    colour     for 
the   two   eyes.       The 
r    result   is   a  beautiful 
-^     lustrous,     translucent 


M    c  r  3^  s  t  a  1,  s  h  o  w  i  n  g 
I    chano-es  of  liMit  and 

^  o  o    ^ 

%  dark    as  the    binocu- 

c  ]ar    strife  enters  into 

f^  effect. 

§        Binocular    contrast 

g  is   so   called   because 

0  the   result   of   a   bin- 
§  ocular  strife  depends 

1  somewhat  on  the  sur- 

B    roundinojs.       In    Fi"-. 

c  ^  c 

3  156  we  would  expect 
§  an  effect  of  bmocular 
m  lustre  and  binocular 
"f  strife.  We  do  get 
§  them,  but,  in  the 
"  neighbourhood  of  the 
most  prominent  points 

of    each    figure,    the 

corresponding  colour 
overpowers  the  other.  Thus,  in  the  neighbourhood  of 
the  angel  Michael  the  white  is  strongest,  while  around 
Lucifer  the  black  overpowers  the  light. 


CHAPTER  XYI 

FEELIXGS,   EMOTIONS,  MOODS 

THE  word  "  feeling  "  is  emploj^ed  in  many  meanings. 
We  speak  of  feeling  hunger  and  thirst,  and  of 
feeling  pain  ;  we  often  say  a  thing  feels  hot  or  cold,  or 
hard  or  soft.  We  also  say  that  love  and  hate,  joy  and 
sorrow,  care  and  hope,  ai*e  feelings ;  and  we  tell  of 
feelings  of  the  beautiful  and  the  ugly,  of  feelings  of 
truth,  honour,  and  virtue. 

The  first  group  of  these  are  what  are  termed 
"sensations"  and  "percepts";  the  second  group  we 
will  call  the  "  emotions."  Here  we  will  limit  the  term 
"feeling"  to  six  different  and  apparently  simple  facts 
that  we  experience,  namely,  like  and  dislike,  stimulation 
and  depression,  tension  and  relaxation. 

The  feelings  can  be  investigated  by  noting  what 
sensations  and  percepts  arouse  them.  For  example, 
we  can  note  what  colours  and  colour-combinations 
please  us  most,  or  we  can  pick  out  first  the  most  pleas- 
ing combination  of  colours,  then  the  next  pleasing,  etc. 

Let  us  consider  first  some  of  the  facts  concerning  our 
feelings  of  liking  and  disliking  that  can  be  learned  by 
introspection.  The  state  of  our  feelings  depends  on 
the  strength  of  the  impression  that  arouses  them.  For 
example,  a  moderately  sweet  taste,  as  of  sugar,  is 
12  177 


178         Thinking,  Feeling,  Doing 

agreeable ;  an  intensely  sweet  taste,  is  disagreeable.  A 
moderate  degree  of  saltiness  is  pleasant,  but  a  strong 
degree  is  distasteful.  Even  a  faint  bitterness,  as  in 
beer,  is  liked  by  many  persons,  while  the  intense  bitter- 
ness of  quinine  is  revolting. 

Feelings  are  connected  with  all  sorts  of  experiences. 
Muscular  exertion,  or  action  of  any  kind,  may  arouse 
feelings.  Moderate  activity  is  generally  pleasurable; 
but  tiredness,  over-exertion,  and  unheal thiness,  may 
bring  about  intense  unpleasantness. 

From  nearly  every  organ  in  the  body  we  receive 
some  sensation.  The  stomach  makes  itself  known  by 
hunger  or  repletion  ;  the  throat  is  heard  from  when 
thirsty.  Each  of  these  sensations  may  arouse  feelings. 
Thus,  hunger  and  thirst  are  disagreeable  ;  repletion  and 
quenching  of  thirst  are  agreeable.  Other  sensations, 
such  as  of  the  liver,  were  originally  very  strong^ 
but  with  advancing  evolution  they  have  to  a  large 
extent  disappeared ;  the  feelings,  however,  still  re- 
main strong.  An  overloaded  stomach  or  a  disordered 
liver  is  liable  to  make  us  look  upon  the  world  in  a 
very  dismal  light ;  the  disagreeable  feeling  from  such 
a  source  has  overpowered  all  the  others. 

The  influence  of  touch  and  temperature  on  our 
likings  for  tastes  is  so  entirely  overlooked  that  scien- 
tists have  been  deceived  into  supposing  that  there  was 
some  actual  chemical  differences  corresponding  to  the 
differences  in  agreeableness  of  taste  between  things 
whereas  the  differences  arise  from  the  mixture  with 
various  touch  and  temperature  sensations, 

A  draught  direct  from  the  old  oaken  bucket  has  a 
taste  quite  different  from  that  of  the  same  water  drunk 


Feelings,  Emotions,  Moods       179 

from  a  glass.  Water  from  a  tin  cup  is  intolerable,  yet 
coffee  from  a  tin  cup  is  far  superior  to  coffee  in  any 
other  way.  The  reason  is  a  purely  psychological  one  ; 
the  different  sensations  of  touch  and  temperature  mingle 
with  the  sensations  of  taste  to  produce  agreeable 
combinations. 

Various  objects  are  liked  or  disliked  according  to 
their  characters.  Strong  bright  colours  are  always 
liked.  Anyone  looking  at  the  rainbow  colours  would 
be  tempted  to  exclaim  :  "  All  colours  are  beautiful !  " 
This  effect  is  very  pronounced  when  the  eye  looks 
directly  at  the  light  thrown  back  by  a  spectrum-grating 
(p.  125) ;  all  the  colours  from  red  to  violet  and  purple 
are  of  an  indescribable  beauty. 

White  itself,  when  not  too  strong,  is  just  as  beauti- 
ful. Since  we  cannot  look  directly  at  the  sun,  the 
light  must  be  weakened  by  reflection.  The  white 
surface  of  snow  possesses  a  beauty  as  great,  if  not  greater, 
than  the  rainbow  colours. 

When  the  colours  are  mixed  with  white,  less  beauti- 
ful colours  are  obtained.  No  pink  can  be  produced 
that  is  equal  to  pure  red ;  no  pale  green  that  is  as 
beautiful  as  pure  green.  The  whitish  skies  of  our 
colder  climates  cannot  be  compared  with  the  deep  blue 
sky  of  Italy.  When  a  colour  or  white  is  darkened,  i.  e. , 
made  less  strong,  its  beauty  is  lessened.  Greys  and 
shades  are  not  comparable  with  full  colours.  It  is  when 
colours  are  mixed  with  white  and  are  also  weakened 
that  indifferent  or  disagreeable  colours  are  obtained. 
Greyish  pinks  or  greyish  browns  or  drab  blues  are 
sombre  and  unpleasant 

In  general  we  can  say :    pure  white  sunlight,  when 


i8o         Thinking,  Feeling,  Doing 

not  too  strong,  is  beautiful ;  the  rainbow  colours  are 
beautiful ;  these  all  become  less  pleasing  when  less 
strong;  the  colours  become  less  pleasing  when  mixed 
with  white  ;  the  most  disagreeable  effects  are  pro- 
duced by  mixtures  of  grey  (weaker  white)  with  shades 
(weaker  colours). 

We  have  thus  far  spoken  only  of  single  colours. 
When  colours  are  combined,  the  combination  may  pro- 
duce an  agreeable  or  a  disagreeable  effect,  depending 
on  the  relation  of  the  two  colours. 

In  the  first  place,  any  combination  of  the  rainbow 
colours  is  agreeable.  In  the  rainbow  or  the  spectrum 
they  are  all  there  together.  In  fact,  when  colours  ap- 
proach the  brilliancy  of  the  rainbow  colours,  as  in 
stained  glass,  almost  any  combination  appears  fairly 
good.  This  is  one  reason  why  the  patterns  in  a  kalei- 
doscope have  been  of  so  little  value  in  decorative  art ; 
when  the  colours  are  most  carefully  imitated  in 
coarser  materials  they  are  apt  to  lose  their  brilliancy 
and  to  produce  disagreeable  effects.  To  a  lesser  de- 
gree this  applies  also  to  silk ;  many  colour  combina- 
tions worked  out  in  this  material  are  tolerable  on 
account  of  their  brightness,  while  the  same  designs  if 
made  in  wool  or  cotton  appear  very  poor. 

Nevertheless,  even  with  the  brightest  spectrum 
colours,  some  pairs  are  more  pleasing  than  others.  If 
the  colours  of  the  spectrum  be  arranged  in  a  circle  so 
that  complementary  colours  (page  125)  are  opposite 
each  other,  it  can  be  laid  down  as  a  rule  established  by 
experiment  that  a  combination  of  two  colours  is  the 
more  agreeable  the  more  nearly  they  are  complementary. 
When  two  greys  are  combined  together,  the  effect  is 


Feelings,  Emotions,  Moods       i8i 

more  pleasing  the  more  they  differ.  White  and  black 
— the  extremes  of  grey — are  the  most  pleasing  of  all 
pairs.  When  a  colour  is  combined  with  grey,  or  when 
two  colours  of  different  shades  or  tints  are  combined, 
the  most  pleasing  effect  is  obtained  when  tlie  difference 
is  greatest.  A  light  red  and  a  dark  green  will  be  better 
than  a  moderately  light  red  and  a  moderately  dark 
green.  Yet  even  this  last  may  be  better  than  a  liglit 
green  and  a  dark  blue,  because  red  and  green  as  colours 
give  better  effects  than  green  and  blue.  To  get  the  full 
effect  we  should  use  double  contrast:  (1)  of  comple- 
mentary colours,  and  (2)  of  light  and  dark.  Foi-  example, 
we  should  combine  bright  red  with  dark  bluish  green 
or  dark  red  with  light  bluish  srreen,  bright  orang^e  with 
dark  blue  or  dark  orange  with  bright  blue,  etc. 

It  must  be  confessed  that  these  statements  are  rank 
heresies  in  decorative  art.  Still,  they  are  the  combina- 
tions preferred  by  unprejudiced  individuals.  The 
bright  colours  and  strong  contrasts  are  preferred  by 
children,  by  savage  tribes,  by  the  peasantry,  and  also 
in  former  periods  of  art. 

Wliy  should  we  not  be  allowed  to  enjoy  the  combina- 
tions of  colour  as  nature  shows  them  to  us?  Nature 
decorates  her  fields,  hills,  and  skies  with  the  most  gor- 
geous colours  ;  we  northern  nations  decorate  our  towns, 
ourhomcs,  and  our  persons  with  the  dullest  combina- 
tions we  can  find.  Any  one  who  attempts  to  put  a 
little  life  into  our  colours  is  decried  as  an  uncultured 
being.  As  Ruskin  says  :  "  The  modern  colour  enthusi- 
asts who  insist  that  all  colours  must  be  dull  and  dirty 
are  just  like  people  who  eat  slate-pencil  and  chalk  and 
assure  everybody  that  they  are  nicer  and  purer  than 


i82         Thinking,  Feeling,  Doing 

strawberries  and  plums.  The  worst  general  character 
that  decorative  colouring  can  possibly  have  is  a  preva- 
lent tendency  to  a  dirty  yellowish  green,  like  that  of  a 
decaying  heap  of  vegetables.  It  is  distinctively  a  sign 
of  a  decay  of  colour  appreciation." 


Fig.  157.— Single  Symmetry, 
Horizontal. 


Fig.  158.— Single  Symmetry. 
Vertical. 


The  products  of  art  please  or  displease  us  not  only 
on  account  of  their  colour  but  also  on  account  of  their 
form.  The  elements  of  space  as  exciting  pleasure  can 
be  classed  into  the  division  of  forms  and  the  direction 
of  bounding  lines. 


Fig.  159.— Double  Symmetry.         Fig.  160.— Threefold  Symmetry. 

In  reg^ard  to  the  division  of  forms,  we  notice  first 
that  regular   forms  are  preferable  to  irregular  ones. 


Feelings,  Emotions,  Moods       183 

The  simplest  kind  of  regularity  is  symmetry,  /.  e.,  the 
likeness  of  the  two  halves.  Horizontal  symmetry,  i.  e., 
likeness  of  parts  on  each  side  of  a  vertical  line,  is  the 

most  preferred.  Double  sym- 
metry is  better  than  single. 
The  more  complicated  the  sym- 
metry becomes,  the  better  we 
like  the  result.  The  degree  of 
symmetry  is  denoted  by  the 
number  of  lines  that  can  be 
drawn  through  the  centre 
FiG.iei.-Fourfoid  Symmetry    whercby  the  half  of  the  figure 

on  one  side  of  the  line  is  just 
the  opposite  of  the  half  on  the  other  side.  A  plain 
circle  is  in  perfect  symmetry  in  every  direction,  but  it 
becomes  much  more  pleasing  when  made  into  a  rosette. 


Fig   162.— Eightfold  Symmetry. 

Another  kind  of  regularity  is  found  in  a  definite 
relation  of  heig^lit  to  breadth.  The 
nerfect  square  is  very  displeasing  be- 
cause, owins^  to  the  overestimation  of 
tiie  vertical  direction  (page  187)  the 
fitzure  appears  to  be  slightly  too  tall  ; 
it  seems  to  impel  us  to  make  it  cor-  _    _„    t,   *   .  •   * 

I-  Fig. 163. —Perfect  out 

rect     As  the  actual  square  is  short-      fn^Sj^'mStTons^ 

ened  we  dislike   it  less,   and,   finally, 

when  it  appears  to  be  a  perfect  square,  we  consider  it 


1 84         Thinkini^,  Feelin^T,  Doing 


a  very  pleasing  figure.  Of  course,  by  actual  measure- 
ment it  is  no  longer  a  square,  but  it  is  a  square  as  far 
as  we  are  concerned. 

If  a  square  be  changed  to  a  rectangle,  it  is  less  pleas- 
ino^  than  before,  unless  there  is  a  certain  relation  be- 
tween  the  length  and  height.  Suppose  in  Fig.  165 
the  square  at  X  to  be  succes- 
sively lengthened  in  the  direction 
X.  Careful  experiments  have 
proven  that  the  degree  of  pleas- 
ure follows  some  such  course  as 
indicated  by  the  line  SGr.  When 
the  relation  of  the  two  sides  is  p 
actually  1  times  1  the  figure  is 
very  displeasing.  When  it  is  equal  to  an  apparent 
square  the  pleasure  is  considerable,  S.  As  it  grows  in 
length  the  pleasure  at  first  decreases,  then  increases 
till  at  a  relation  1 : 1.618  it  is  at  a  maximum,  G. 

We  have  now  reached  the  border-land  between  psy- 


164.— Combinations    of 
Symmetry. 


Fig   105.— The  Law  of  Pleasing  Relations  of  the  Dimensions  of  a  Rectangle. 

chology  and  the  aesthetics  of  form,  and  at  the  same 
time  W3  have  come  to  the  end  of  our  definite  experi- 
mental knowledge.  The  writers  on  architecture,  paint- 
ing, drawing,  and  decoration  have  produced  numberless 
speculations  on  the  psychological  principles  underly- 


Feelings,  Emotions,  Moods        185 

incr  the  beautiful  and  the  ualv.  How  far  each  is  ris^ht 
we  cannot  saj;  as  psycliologists  we  have  no  call  to 
meddle  till  experimental  evidence  can  be  produced. 

The  recognition  of  four  forms  of  feeling  in  addition 
to  liking  and  disliking  we  owe  to  Wiindt ;  the  rest  of 
the  chapter  is  based  on  his  work. 

We  are  all  accustomed  to  characterise  various  ex- 
periences as  "  stimulating,"  others  as  "  quieting "  or 
"  depressing.''  To  the  former  we  usually  reckon  bright 
colours,  high  tones,  lively  melodies,  etc.;  to  the  latter 
dull  colours,  low  soft  tones,  soothing  melodies. 

The  third  pair  of  feelings  can  be  illustrated  when 
we  listen  at  the  telephone  for  the  answer  to  oar  call. 
The  thought  of  the  answer  arouses  a  steadily  growing 
feeling  to  "tension,"  which  is  changed  to  one  of 
"relaxation"  when  the  answer  actually  comes. 

The  six  feelings  are  often  combined.  Tension  is 
sometimes  pleasurable ;  the  cat  plays  with  tlie  mouse 
before  eating  it.  Tension  may,  however,  be  combined 
with  dislikes,  the  peacock  who  lived  next  door  to  De 
Quincy  almost  maddened  liim  by  the  expectation  of 
the  coming  scream  ;  the  actual  scream  was  a  relief.  It 
is  related  that  a  guest  on  going  to  bed  dropped  his  shoe 
noisily  on  the  floor,  but,  remembering  that  his  host  was 
a  very  nervous  man,  he  put  the  other  down  noiselessly  ; 
not  long  afterward  the  latter  appeared  excitedly  at  the 
door,  exclaiming  "Why  in  thunder  don't  you  take  off 
the  other  shoe  ?  "  The  disasrreeable  tension  was  strono^er 
than  courtesy. 

The  feelmgs  can  also  be  investigated  by  studying 
their  effects  on  the  breathing,  on  the  heart,  and  on  the 
blood  vessels.     For  the  study  of  breathing  a  rubber- 


i86        Thinking,  Feeling,  Doing 

topped  receiving  capsule  is  so  placed  over  the  abdomen 
or  the  chest  that  the  recording  capsule  connected  with  it 
(Fig.  43)  will  register  the  breathing  movenaents. 

Records  of  the  action  of  the  heart  and  the  blood  vessels 
may  be  obtained  with  the  sphygmograph  or  tlie  plethys- 
mograph.  In  the  sphygmograph  the  receiving  capsule 
is  so  placed  over  the  wrist  that  the  rubber  top  receives 
impulses  from  the  pulse-beat;  the  recording  capsule  is 
arranged  as  usual  so  that  the  pulse-beat  is  registered  on 
a  smoked  drum. 

In  the  plethysmograph  the  arm  is  placed  in  a  cylinder 
and  a  rubber  cuff  is  tightened  around  it;  the  cylinder 
is  then  filled  with  water.  A  recording  capsule  is  con- 
nected to  it.  When  blood  is  drawn  from  the  arm,  it 
shrinks  in  volume,  and  air  is  drawn  from  the  recording 
capsule  ;  when  more  blood  flows  to  the  arm,  the  reverse 
occurs.  Thus  the  plethysmograph  furnishes  records  of 
variations  of  the  amount  of  blood  in  the  arm.  These 
variations  arise  from  contraction  and  relaxation  of  tiie 
blood  vessels  (  arteries  and  capillaries  ).  At  the  same 
time  the  plethysmograph  registers  the  pulse-beat. 

The  effects  of  the  feeling  of  tension  may  be   illus- 


FiG.  166. — Effect  of  Attention  on  Respiration. 

trated   by  Fi.e.    166.      The   line   registers    the   cliest 
breathing.     The  first  two  breaths  are  before  the  ex- 


Fig.  167.— Effect  of  Attention,  Plethysmcgraph  Record. 


Fig.  168. — Respiration  and  Arm  Curve  during  Tension  and  Relaxation 


Fig.  169.— Effect  of  a  Stimulating  Thought 
187 


Fig.  170.— Effect  of  a  Depressing  Thought. 


Fig.  171.— Effect  of  Dislike 


z88 


Feelings,  Emotions,  Moods     189 

periment  begins.  At  the  moment  marked  by  the  first 
line  the  subject  begins  to  count  mentally  a  group  of 
dots;  at  the  second  line  he  finishes.  The  curve  shows 
that  during  his  counting  his  inspirations  become  less- 
ened ;  this  is  due  to  a  general  tension  of  the  breathing 
muscles. 

The  plethysmograph  record  in  Fig.  167  shows  the 
effect  of  attracting  attention  by  lightly  touching  a 
person.  The  volume  of  the  arm  diminishes  owing  to 
general  contraction  of  its  blood  vessels  ;  the  pulse-beat 
becomes  less  and  its  time  slower. 

The  feeling  of  relaxation  is  readily  studied  by  re- 
quiring the  subject  to  do  some  mental  addition  or 
multiplication.  The  breathing  and  plethysmograph 
curves  at  the  end  of  one  experiment  are  shown  in  Fig. 
168.  At  h  the  subject  has  finished  multiplying  93  by  78. 
The  top  record  shows  that  his  breathing  becomes 
strong^er.  Tlie  other  record  shows  that  the  volume 
of  the  arm  and  the  height  of  the  pulse  beat  increased, 
but  the  time  of  the  pulse  beat  remains  the  same. 

Fig.  169  shows  breathing  and  plethysmograph  re- 
cords after  a  stimulating  thought  occurring  at  a.  The 
pulse  is  strengthened,  but  not  essentially  changed  in 
period  ;  the  respiration  is  strengthened  but  not  other- 
wise altered.  Exactly  the  opposite  is  seen  in  Fig.  170. 
A  depressing  thought  was  present  from  h  to  c.  The 
pulse  is  weakened  (the  slight  acceleration  is  due  to  the 
feeling  of  dislike).  The  breathing  is  shallow  and  very 
irregular.  After  tlie  thought  passes  at  c  the  breathing 
rapidly  becomes  normal,  and  the  pulse  slowly  so. 

The  feelings  of  stimulation  and  depression  are  usually 
mixed  with  those  of  tension  and  relaxation.     For  ex- 


iQO        Thinking,  Feeling,  Doing 

ample,  when  a  person  is  solving  an  intellectual  problem 
he  has  often  feelings  not  only  of  tension  but  also  of 
stimulation  (or  excitement) ;  the  excitement  often  lasts 
when  the  tension  has  been  replaced  by  relaxation.  The 
pulse  curve  in  such  a  case  shows  stronger  beats  during 
the  first  period  instead  of  the  weaker  ones  that  accom- 
pany tension  alone;  during  the  relaxation  they  are 
increased  more  than  usual  because  the  stimulation 
continues  to  be  present. 

A  record  during  dislike  is  shown  in  Fig.  171.  The 
disagreeable  taste  at  h  produces  a  sudden  stoppage  in 
the  breathing  which  was  followed  by  deeper  and  slower 
breathing.  The  volume  of  the  arm  becomes  less  ;  the 
pulse  becomes  less  marked  and  slower.  Eecords  dur- 
ing the  feeling  of  liking  show  just  the  opposite. 

The  results  in  relation  to  breathing  and  pulse  may 
be  summarised  as  follows : 

BREATHING  PULSE 

Tension  :  slowed,    strengthened  slowed,  weakened 

Relaxation  :  accelerated,  strengthened    accelerated,  strength- 
ened 
Stimulation  :  accelerated,  strengthened    unchanged  in  period, 

strengthened 
Depression  :  slowed,  strengthened  unchanged  in  period, 

weakened 
Like  :  accelerated,  weakened  slowed,  strengthened 

Dislike  :  slowed,  weakened  accelerated, weakened 

When  a  strong  feeling  arises  in  connection  with  any 
percept  or  thought,  it  may  have  an  effect  on  our  fol- 
lowing thoughts  and  acts,  which  persists  for  some  time. 
Thus,  the  sight  of  a  certain  person  may  cause  a  feeling 
of  dislike  to  arise,  and  both  may  then  initiate  a  train  of 
thoughts,  feelings,  and  expressions  that  we  call  anger. 


Feelings,  Emotions,  Moods      191 

The  entire  complex  of  feelings,  thoughts,  and  expres- 
sions we  may  call  an  "  emotion." 

According  as  the  elements  of  liking  or  those  of  dis- 
liking predominate,  we  have  agreeable  emotions,  such 
as  pleasure  and  joy,  or  disagreeable  ones  such  as 
chagrin  and  sorrow.  Strangely  enough  our  language 
has  no  term  for  that  most  common  emotion :  the  oppo- 
site of  pleasure.  Suppose  that  you  unexpectedly  find  an 
autograph  letter  of  George  Washington  among  old 
papers  in  your  attic;  this  would  give  you  great  pleas- 
ure. Now  suppose  that  you  lose  it :  your  emotion 
would  be — what?  You  might  say  "sorrow,"  but 
the  emotion  is  certainly  not  the  same  as  if  you  had 
heard  of  the  death  of  a  parent.  "  Pain  ?  " — the  emotion 
has  no  resemblance  to  the  sensation  of  pain  from  the 
point  of  a  needle  except  in  having  the  element  of 
dislike  in  it.  "Displeasure''  might  be  the  term,  but 
it  is  used  only  when  the  opposite  of  pleasure  refers  to 
some  one's  act 

The  predominance  of  the  feeling  of  stimulation  or 
depression  produces  the  stimulant  and  depressant 
emotions ;  to  the  former  belong  joy  and  anger,  to  the 
latter  sorrow  and  fear.  The  feeling  of  tension  pre- 
dominates in  the  tonic  emotions,  joy,  anger,  terror ;  that 
of  relaxation  in  sorrow  and  despair. 

Under  "  moods  "  we  may  classify  conditions  of  mind 
that  colour  all  our  thoughts,  emotions,  and  acts.  We 
find  two  characteristic  principles  in  the  moods.  The 
first  we  may  term  "tonality;"  its  positive  extreme  is 
"exaltation,"  its  negative  one  "depression."  The 
other  wa  may  term  "activity,"  with  "excitability"  as 
one  extreme  and  "  apathy  "  as  the  other. 


19^         Thinking,  Peeling,  Doing 

Excitability  indicates  over-readiness  to  respond  to 
stimuli  of  all  kinds:  impressions,  thoughts,  feelings. 
Apathy  indicates  lack  of  response. 

Exaltation  shows  itself  in  increased  facility  and 
rapidity  of  thought,  in  preponderance  of  the  positive 
feelings  (liking,  stimulation,  tension),  in  increased 
rapidity  and  energy  of  action,  increased  estimation  of 
one's  self,  in  optimistic  views  of  persons  and  events, 
etc. 

Depression  is  characterised  by  the  negative  feelings 
in  slowness  and  difliculty  of  thouglit,  in  weakness, 
uncertainty,  and  slowness  of  action,  in  self -depre- 
ciation. 


CHAPTER    XYII 

ATTENTION 

WHAT  is  this  difference  between  attention  and 
inattention,  between  expectation  and  surprise? 
How  can  we  turn  inattention  into  attention  ? 

When  you  first  move  into  a  new  neighbourhood,  you 
notice  every  house,  every  tree,  almost  every  stone,  as 
you  pass  to  and  fro.  As  you  grow  accustomed  to  the 
surroundings,  you  gradually  cease  to  notice  them. 
Finally  you  pay  so  little  heed  to  them  that  you  are 
unable  at  the  end  of  a  walk  to  tell  what  you  have  just 
seen  by  the  way.  This  fact  is  expressed  by  saying 
that  at  first  you  attended  to  what  you  saw  and  after- 
wards did  not. 

I  can  illustrate  this  process  of  attention  in  another 
way.  You  are  now  reading  the  sentences  on  this  page; 
you  are  giving  full  attention  to  what  I  say.  But  at 
the  same  time  you  are  receiving  touch  impressions 
from  the  book  in  your  hand  and  from  the  clothes  you 
wear ;  you  hear  the  waggons  on  the  street  or  the  howl- 
ing of  the  wind  and  the  rustling  of  the  trees ;  you 
smell  the  roses  on  the  table.  Now  that  I  have 
mentioned  them  you  notice  them — or  pay  attention 
to  them.  When  you  were  attending  to  what  you 
w^ere  reading,   they  were  only  dimly   present. 

I  will  suppose  that  you  are  attending  to  what  you 

193 
13 


194  Thinking,  Feeling,  Doing 


are  reading;  all  those  sounds,  touches,  smells,  etc.,  are 

only  dimly  in  the  field  of  your  experience  while  these 

words  are  in  the  focus  (or  burning-point)  of  experience. 

Probably  you  can  gain  a  good  idea  of  the  difference 

between  the  focus 
and  the  field  of 
present  experience 
by  taking  an  anal- 
ogy from  the  art 
of  photography. 
When  the  ground 
glass  of  a  camera  is 
adjusted  so  that  the 
picture  of  a  person 
in  the  middle  of 
the  room  is  sharply 
seen,  all  the  other 

Fig.  172.— Focus  and  Field  of  Attention.         obiccts     are     SOmC- 

what  blurred,  depending  on  their  distance  from  him. 
When  the  position  of  the  glass  is  changed  by  a  trifle, 
the  person  becomes  blurred  and  some  other  object  be- 
comes sharp.  Thus  for  each  position  of  the  glass 
there  is  an  object,  or  a  group  of  objects,  distinctly  seen 
wdiile  all  other  objects  are  blurred.  To  make  one  of 
the  blurred  objects  distinct,  the  position  of  the  glass 
must  be  changed  and  the  formerly  distinct  object 
becomes  blurred. 

In  like  manner  we  fully  attend  to  one  object  or  group 
of  objects  at  a  time;  all  others  are  only  dimly  noticed. 
As  we  turn  our  attention  from  one  object  to  another, 
what  was  formerly  distinct  becomes  dim. 

The  illustration  with  the  camera  is  not  quite  com- 


Attention  195 

plete.  You  can  keep  the  objects  quiet  in  the  room, 
but  you  cannot  keep  your  thoughts  still.  The  mental 
condition  would  be  more  nearly  expressed  by  pointing 
the  camera  down  a  busy  street.  You  focus  first  on 
one  thing,  then  on  another.  The  things  in  focus  pass 
out  of  it,  others  come  in.  Only  by  special  effort  can 
you  keep  a  moving  person  or  waggon  in  focus  for  more 
than  a  moment. 

Let  us  ask  a  few  practical  questions. 

In  the  first  place,  How  many  objects  can  be  at- 
tended to  at  a  time?  Objects  can,  of  course,  be  more 
or  less  complicated.  A  house,  for  example,  is  a  single 
object  if  we  do  not  look  into  the  details  ;  it  is  a  multi- 
tude if  we  count  the  windows,  doors,  roof,  chimneys, 
etc.,  as  separate  objects.  By  the  word  "object,''  then, 
we  will  understand  any  thing  or  group  of  things 
regarded  as  a  smgle  thing.  Thus,  the  natural  tendency 
would  be  to  regard  the  letters  MXRVas  four  objects, 
namely,  four  letters,  whereas  MORE  would  be  re- 
garded as  one  object,  namely,  a  word,  unless  we  stop 
to  consider  the  letters  separately. 

Experiments  are  made  by  exposing  pictures,  letters, 
words,  etc.,  to  view  for  a  brief  time.  One  way  of  doing 
this  is  to  prepare  slides  for  the  projection-lantern  and 
throw  the  view  on  the  screen  for  an  instant. 

A  more  convenient  way  is  to  fix  the  pictures  or  let- 
ters on  cards  or  to  prepare  a  table  on  which  actual  ob- 
jects are  placed.  A  photographic  camera  with  a  quick 
shutter  is  aimed  at  them.  The  person  experimented 
upon  is  so  placed  that  he  cannot  see  the  objects,  but  can 
see  the  ground  glass.  Various  other  methods  for  brief 
exposures  have  been  used. 


19^         Thinking,  Feeling,  Doing 

Experiments  of  this  kind  show  that  four,  and  some- 
times even  five,  disconnected  letters,  numerals,  colours, 
etc.,  can  be  grasped  at  the  same  time.  When  the 
objects  are  so  arranged  that  they  enter  into  combina- 
tions that  make  complex  objects,  many  more  can  be 
grasped.  Thus,  two  words  of  two  syllables,  each  word 
containing  six  letters,  can  be  grasped  as  readily  as  four 
single  letters. 

This  ability  to  grasp  and  rem^ember  complicated  ob- 
jects increases  with  age.  Children  seem  to  grasp  only 
the  details  separately  and  to  be  unable  to  gain  a  gen- 
eral view  with  the  parts  in  proper  subordination.  In 
drawing  a  horse  unskilful  persons  begin  with  the 
head,  proceed  with  the  back,  then  the  rear  legs,  etc., 
thinkmg  of  only  one  thing  at  a  time;  the  result  is 
generally  that  the  various  parts  are  out  of  propor- 
tion. The  details  are  often  so  isolated  in  the  child's 
mind  that  he  will  draw  parts  entirely  separated  from 
one  another.  This  is  the  case  with  the  child  that  drew 
an  oblong  and  a  square  separately  to  stand  for  the  two 
sides  of  a  box  seen  in  perspective. 

Let  us  consider  next  the  methods  of  forcing  attention 
to  an  object,  or  as  is  frequently  said,  of  forcing  the 
object  into  attention. 

The  first  law  I  shall  state  is:  Bigness  regulates  the 
force  of  attention.  Young  children  are  attracted  to 
objects  by  their  bigness.  Advertisers  know  that  one 
large  advertisement  is  worth  a  multitude  of  small  ones. 
A  certain  life  insurance  company  puts  up  the  biggest 
building;  a  newspaper  builds  the  highest  tower. 
Churches  frequently  vie  in  building,  not  the  most 
beautiful,  but  the  largest  house  of  worship. 


Attention  i97 

The  second  law  of  attention  which  I  venture  to  pro- 
pose is  the  law  of  intensity  or  brightness^  according  to 
which  the  intensity  of  a  sensation  influences  the  amount 
of  attention  paid  to  it.  Here  also  we  have  no  experi- 
mental results ;  we  must  for  our  examples,  rely  on  the 
art  of  psychology  rather  than  on  the  science. 

The  shopkeeper  well  knows  the  effect  of  a  gilded 
sign.  The  druggist's  bright  light  forces  you  to  notice 
him.  The  headlight  on  the  trolley-car  serves  a  purpose 
in  addition  to  lighting  the  track. 

The  clanging  gong,  the  excruciating  fish-horn,  the 
rooster's  crow,  and  tlie  college  yell  are  all  for  the  pur- 
pose of  attracting  attention.  Full  black  letters  for 
paragraph  headings  or  advertisements  are  more  efl'ec- 
tive  than  ordinary  type  or  outline  letters. 

Cleanliness  is  not  the  only  reason  why  a  man-of-war 
is  kept  in  a  high  degree  of  polish.  The  furnishings 
could  be  just  as  clean  if  painted  with  black  asphalt, 
but  the  effect  on  the  officers  and  men  would  be  quite 
different.  It  is  difficult  to  get  full  attention  to  duty 
and  discipline  in  a  dingy  vessel. 

This  same  principle  is  applied  in  instruction.  An 
old  or  rusty  piece  of  apparatus  cannot  command  the 
same  attention  from  the  students  as  a  brightly  var- 
nished and  nickel-plated  one. 

Students  in  a  chemical  laboratory  do  not  pay  nearly 
as  good  attention  to  their  manipulations  if  they  work 
over  scorched,  stained  tables  and  black  sinks.  The 
director  of  one  laboratory  in  Belgium  covers  his  tables 
with  fine,  white  lava-tops.  The  expense  is  at  first 
great,  but  the  increased  attention  more  than  repays  the 
cost.     Experience  has  shown  that  the  students  working 


iqS        Thinking,  Feeling,  Doing 

at  those  tables  keep  their  glassware  cleaner  and  do 
their  chemical  work  with  more  care  than  those  who 
work  at  the  ordinary  wooden  tables. 

The  third  law  I  shall  call  the  law  of  feeling;  it  can 
be  stated  in  this  way  :  The  degree  of  attention  paid  to  an 
object  depends  on  the  intensity  of  the  feeling  aroused.  The 
feeling  may  be  either  of  liking  or  disliking. 

Painful  sensations  arouse  a  strong  dislike.  "  The 
burned  child  dreads  the  fire  "  ;  it  is  equally  true  that  a 
burned  child  watches  the  stove.  The  very  name  of 
croup  strikes  terror  into  the  mother  and  the  slightest 
lioarseness  arouses  her  attention. 

Few  feelings  are  so  intensely  pleasurable  as  those  of 
the  young  mother.  Watch  the  tension — the  attention — 
to  every  movement  of  the  child. 

In  former  days  beautiful  objects  were  accompanied 
by  intensely  pleasurable  feelings.  When  Giotto  wished 
to  give  Florence  a  remarkable  tower,  he  made  it  of 
wondrous  beauty.  When  the  Parisians  wished  a  strik- 
ing tower  for  their  exposition,  they  got  M.  Eiffel  to 
make  it  the  tallest  one. 

To  celebrate  the  victory  of  his  chorus  in  the  theatre 
of  Bacchus,  Lysikrates  erected  in  Athens  his  famous 
choragic  monument.  Exquisitely  wrought,  graceful 
in  its  proportions,  rich  in  decoration,  perfect  in  its  ma- 
terial, it  is  the  wonder  and  admiration  of  the  world. 
True,  it  is  only  thirty-four  feet  tall,  and  to-day  in  com- 
petition with  the  Ferris  wheel  would  not  attract  the 
slightest  attention — unless  it  could  be  used  as  the 
ticket-office. 

In  fact,  our  crude  western  civilisation,  our  puri- 
tanical love  of  the  ugly,  and  our  blind  worship  of 


Attention  199 

bigness  have  deprived  us  of  any  feeling  for  beautiful 
objects.  If  an  appeal  is  to  be  made  for  attention 
through  feeling,  it  must  be  done  in  some  other  way. 
The  other  way  is  generally  by  use  of  the  comic,  the 
grotesque,  or  the  hideous ;  for  example,  the  alleged 
jokes  that  are  interspersed  all  through  our  news- 
papers, the  cartoons  of  a  political  campaign,  and 
the  silly  coloured  supplements  of  the  Sunday  papers. 

Personal  pride  is  accompanied  by  a  strong  feeling 
which  brings  attention  to  anytliing  necessary  for  its 
proper  maintenance.  Vanity  is  an  excessive  degree  of 
personal  pride;  it  is  a  most  powerful  incentive  to 
attention. 

The  culminating  point  in  education  is  the  power  to 
attend  to  things  that  are  in  themselves  indifferent  by 
arousing  an  artificial  feeling  of  interest.  There  is 
hardly  anything  of  less  intrinsic  interest  to  the  student 
than  analytical  mathematics,  such  as  algebra;  the 
treatment  is  purposely  deprived  of  every  concrete  re- 
lation. Yet  we  know  that  the  power  of  attending  to 
such  a  subject  can   be  cultivated. 

The  fourth  law  of  attention  which  I  shall  propose  is 
the  law  of  expectation — I  had  almost  said  of  curiosity. 

A  step  at  the  front  door  arouses  a  memory  of  a  bell- 
ring  ;  the  ear  is  prepared  to  hear  it  Whether  the 
matter  concerns  us  or  not,  this  condition  of  expectation 
forces  our  attention. 

The  peacock  which  lived  next  door  to  De  Quincey  al- 
most maddened  him  by  the  expectation  of  the  coming 
scream.  The  actual  scream  was  a  relief ;  thereafter 
the  attention  became  steadily  more  and  more  intense 
till  the  moment  of  the  next  scream.     The  law  of  ex- 


200        Thinking,  Feeling,  Doing 

pectatioa  is  used  in  a  masterly  way  in  Dickens's 
Mutual  Friend.  It  is  a  characteristic  of  successful  news- 
paper writing  that  the  opening  paragraph  shall  arouse 
expectation,  and  therefore  attention.  The  same  princi- 
ple underlies  the  art  of  writing  headlines. 

Scientific  men  are  famed  for  strict  and  ardent  atten- 
tion to  their  investigations.  The  fascination  of  re- 
search and  discovery  lies  in  the  vague  expectation  of 
something  new.  The  essence  of  all  science  is  curi- 
osity— the  plain  every-day,  good  old  homely  curiosity 

that  impels  Farmer  B 's   wife  to  learn  just  how 

many  eggs  are  laid  by  her  neighbour's  hens,  that  makes 
Robbie  pull  apart  his  tin  locomotive  to  see  how  it 
works,  or  that  induces  a  cat  to  stick  her  j^aw  down 
a  knot-hole  in  the  floor. 

Unsatisfied  curiosity  arouses  still  more  attention. 
Many  papers  still  maintain  puzzle  columns,  well  know- 
ing that  unsatisfied  curiosity  is  a  more  intense  form  of 
unsatisfied  expectation.  The  reason  of  the  great 
attention  paid  to  Stockton's  The  Lady  or  the  Tiger 
is  to  be  found  here. 

It  is  a  principle  of  serial  stories  that  each  instal- 
ment shall  end  with  an  unsatisfied  expectation.  This 
contributes  more  than  the  merit  of  the  story  to  arous- 
ing the  attention  of  the  reader,  who,  because  he  keeps 
thinking  of  what  may  happen,  is  forced  to  buy  the 
next  number  of  the  periodical  in  order  to  be  relieved 
of  the  tension. 

The  fifth  law  of  attention  is  the  laxv  of  change^  or  the 
law  of  unexpectedness ;  the  degree  of  attention  depends 
upon  the  amount  and  on  ilie  rapidity  of  the  change. 

Things  indifferent  and  even  things  unpleasing  may 


Attention  201 

leave  their  impress  by  the  severity  of  the  shock  they 
give.  A  flash  of  lightning  or  a  low  door-lintel  com- 
mands notice.  There  is  an  old  saying  that  wonder  is 
the  beginning  of  philosophy.  Various  things  may  be 
meant  by  wonder,  but  one  thing  is  the  shock  of  mere 
surprise  or  astonishment ;  at  any  rate  an  impression  is 
made. 

In  our  reading  we  expect  only  straight  lines.  The 
advertiser  arouses  attention  by  tipping  them  slantwise. 
The  advertiser  makes  frequent  use  of  this  law  com- 
bined with  the  law  of  curiosity  by  putting  in  his 
notice  upside  down. 

A  prominent  effect  of  attention  is  to  shorten  reac- 
tion-time and  thought-time  and  make  them  more 
regular.  The  commands  of  a  military  captain  are 
really  signals  for  reaction.  The  first  part  of  a  military 
command  is  arranged  to  serve  as  a  warning  signal  to 
insure  good  attention  ;  "  Shoulder — ARMS  !  "  "  Right 
— FACE  !  "  The  acts  of  the  men  are  simple  reactions. 
They  are  not  associations  ;  therein  lies  the  reason  wliy 
a  command  is  not  given  as  a  single  expression.  If  the 
command  were  "  Forward-march,"  delivered  as  one 
expression,  the  soldier  would  be  obliged  to  discrim- 
inate, associate,  and  choose  among  twenty  or  thirty 
possible  commands.  We  have  already  seen  that  these 
processes  not  only  take  a  very  long  time  bat  are  very 
irregular;  moreover,  no  warning  would  have  been 
given.  The  company  could  not  possibly  step  forward 
as  one  man,  wdiereas  the  command  "  Forward — 
MARCH  "  causes  all  the  mental  processes  except  sim- 
ple reaction  to  be  performed  beforehand  ;  every  man  in 
the   company   has   but   one   thing  to   do,    his   atteu- 


202         Thinking,  Feeling,  Doing 

tion    has   been    properly    prepared    by    the   warning 
and  the  whole  company  should  start  together. 

A  notable  effect  of  attention  to  one  idea  is  the  lack 
of  attention  to  other  ideas.  Henry  Clay  was  obliged 
to  speak  on  one  occasion  when  in  very  delicate  health. 
He  asked  a  friend  who  sat  beside  him  to  stop  him 
after  twenty  minutes.  When  the  time  had  passed 
the  friend  pulled  Clay's  coat,  but  he  continued  to 
speak.  His  friend  pinched  him  several  times  and 
finally  ran  a  pin  into  his  leg.  Clay  paid  no  attention. 
He  spoke  for  more  than  two  hours  and  then,  sinking 
exhausted,  he  upbraided  his  friend  for  not  givmg  him 
a  signal  to  stop  at  the  proper  time.  The  signals  had 
been  given  but  his  mind  was  so  intensely  attentive  to 
his  discussion  that  evervthino-  else  was  neoflected.  It 
is  a  well-known  fact  that  we  can  forget  griefs,  pains, 
even  the  toothache,  when  readingi;  a  fascinatino-  book 
or  watching  a  forcible  drama. 

Going  stdl  further  we  find  abnormal  cases :  arithmo- 
mania,  where  the  patient  is  continually  askmg  why 
houses  are  so  large,  why  the  trees  are  so  tall,  or  where 
he  is  continually  countmg  the  number  of  paving-stones 
m  the  street  or  the  number  of  rivers  in  a  country 
metaphysical  mania,  where  the  patient  cannot  hear  a 
word  like  "good,"  "beautiful,"  "being,"  etc.,  without 
irresistibly  speculating  on  the  problems  of  ethics, 
aesthetics,  and  metaphysics.  These  and  similar  cases 
are  included  under  the  term  of  "  fixed  ideas."  The 
acute  stage  of  excessive  att^otjrvn.  is  found  in  ecstasy. 


CHAPTER  XVIII 

MEMORY 

BY  "  memory  "  we  refer  to  the  relation  between  two 
ideas  occurring  at  ditferent  times,  whereby  the 
second  is  intended  to  be  like  the  first.  In  some 
schools  of  design  the  model  is  shown  for  a  short  time, 
whereupon  the  pupils  are  required  to  draw  from  mem- 
ory. The  original  impression,  sometimes  called  the 
sense-perception,  was  that  of  the  model ;  the  memory 
picture  is  the  mental  picture  from  which  the  drawing 
is  made.  The  relation  between  the  two  pictures  is 
the  problem  of  memory. 

There  are  numberless  entertaining  stories  concern- 
ing great  and  peculiar  memories,  but  it  is  much  to  be 
doubted  if  anything  of  any  value  is  gained  by  repeat- 
ing them.  Instead  of  following  the  beaten  path  it  will 
be  better  to  enter  at  once  into  the  experimental  work 
on  the  subject 

Memory  can  be  investigated  in  two  ways :  by  meas- 
uring the  difference  of  the  repeated  idea  from  the 
original,  or  by  counting  the  number  of  successfully 
repeated  ideas  out  of  the  total  number. 

Memory  for  actions  is  a  good  subject  to  begin  with. 
How  accurately  does  the  arm  remember  a  straight 
movement  ?     With  the  eyes  closed  draw  on  the  first 

203 


2C4         Thinking,  Feeling,  Doing 

sheet  of  a  pad  of  paper  a  vertical  line  of  any  agreeable 
length.  Without  opening  the  eyes  tear  off  this  sheet ; 
it  is  very  convenient  to  have  the  pad  fixed  firmly  to 
the  table.  After  waiting  five  seconds  (if  you  have  no 
ticking  clock  at  hand,  some  one  can  tell  you  the  time), 
with  the  eyes  still  closed  draw  a  second  line  which  you 
judge  equal  to  the  first.  Tear  off  the  sheet  as  before. 
After  waiting  five  seconds  again,  draw  a  third  line  of 
the  same  length  as  the  second  (you  need  not  attempt  to 
recall  the  first).  Continue  in  this  way  till  eleven 
lines  have  been  drawn  from  memory. 

With  a  millimetre  scale  (or  a  ruler  divided  into 
sixty-fourths  of  an  inch)  measure  each  line.  The  dif- 
ference between  each  line  and  it^  predecessor  gives  the 
amount  of  error  in  remembering  after  the  particular 
five  seconds.  Thus,  with  a  line  about  100  millimetres 
long,  we  might  get  a  series  of  errors  of  —  2,  —  1,  -|-  1, 

—  1,  +  2,  —  1,  —  3,  —  2,  —  3,  —  1,  where  +  indi- 
cates that  the  second  line  was  too  long  and  —  that  it 
was  too  short. 

In  memory  there  are  two  changes  that  go  on :  first, 
an  actual  change  in  the  idea  remembered;  and,  second, 
an  increasing  uncertainty. 

If  we  average  up  all  the  errors,  taking  into  account 
the  signs,  we  shall  get  the  average  change.  Thus,  the 
average  of  the  set  we  have  just  noticed  is 

—  2-1  +  1-1  +  2-1-  3-2-3- 1_-  11 

10  ~     lO^ 

=  —  1  -jJ^  or—  1.1  ^^. 

This  is  the  average  change  introduced  by  the  lapse  of 
five  seconds. 

What  is  the  uncertainty  of  our  judgment  ?     This  we 


Memory 


205 


find. by  averaging  all  the  separate  errors  without  regard 
to  sign ;  thus 

2  +  l  +  l  +  lH-2  +  l  +  3  +  2  +  3  +  l_17 


10 
=  1 


10 


^or  1.7"^°^. 


We  would  thus  say  that  the  average  uncertainty  intro- 
duced by  a  lapse  of  five  seconds  is  1.7°^. 

By  repeating  the  experiments  with  an  interval  of  ten 
seconds,  we  find  the  average  memory-change  and  the 
average  uncertainty  due  to  that  interval.  Likewise 
we  can  use  intervals  of  fifteen  seconds,  thirty  seconds, 
one  minute,  five  minutes,  etc. 

From  the  results  of  experiments  of  this  kind  that  I 
have  made  the  fundamental  law  of  memory  can  be  de- 
duced as  follows:  The  average  change  is  an  individ- 
ual  matter    depend- 


mg  on  circumstances, 
but  the  average  un- 
certainty increases  in 
a  definite  relation  to 
the  time. 

In  learning  to  write 
by  means  of  a  copy- 

FiG.  173.— A  Leaf  from  Daisy's  Copy-book,  book  the  eye  gets  the 

mental  image  and  then,  looking  down,  guides  the  pen. 
As  the  distance  from  the  copy  to  the  line  grows  larger, 
the  eye  has  time  to  partially  forget  the  exact  form  of 
the  lines  in  the  copy  (Fig.  173). 

The  memory  for  the  force  of  action  can  be  investi- 
gated with  the  dynamometer,  described  on  page  69. 
The  pull  is  executed  to  any  desired  weight.  After 
five  seconds  it  is  repeated   to   apparently  the   same 


2o6         Thinking,  Feeling,  Doing 

weight  The  amount  of  the  error  is  recorded  by 
some  other  person.  Again  after  five  seconds  the 
pull  is  repeated,  and  so  on.  The  average  change  and 
the  average  uncertainty  are  calculated  as  before. 

Then  ten  seconds,  fifteen  seconds,  and  so  on,  are 
used  as  intervals.  We  finally  obtain  the  law  of  mem- 
ory for  force.  The  results  of  an  investigation  lately 
made  show  a  rapid  increase  both  of  the  average  change 
and  the  average  uncertainty. 

The  very  carious  fact  of  cross- education  has  been 
noticed  on  pages  22,  66,  72,  and  85  ;  there  is  also  a 
"  cross-memory." 

If  the  original  line  in  the  experiments  on  page  240 
be  drawn  with,  say,  the  left  hand,  it  can  be  remem- 


bered with  the  right 


o 


R 


hand.     If  the  orig- 
inal  pull   on    the    S  st^mm/^         /yyu^yyurMY/ 
dynamometer  be  ^  / 
made    with  one    ^          ,?t^,..v<77^ 
hand,  it  can  be  re-                         </ 
membered  with  the 
other. 

A    most   curious 
fact  about  this  cross- 


v-flMuA  Xiyyyvi/ 


D  AurvYV\^ 


memory  is  that  the  ^'°-  ■^^^•~^^'"remo?y.^°'^  ^"^^""^  ^'''''' 
memory  for  movements  is  sj^mmetrical  and  not 
identical.  We  learn  to  write  with  the  right  hand  ; 
when  we  attempt  to  write  with  the  left  we  succeed 
fairly  well  by  writing  outward  {i.  e.,  backward),  just 
as  the  right  hand  wrote  outward,  but  we  cannot  write 
as  well  in  the  regular  direction.  Here  are  two  speci- 
mens (Fig.   174).     By  looking  at  the   words  with  a 


Memory  207 

mirror  it  will  be  seen  that  with  the  left  hand  those 
written  outward  are  better  than  those  written  inward. 
When  the  eyes  are  open  during  this  experiment,  the 
preponderance  of  the  visual  picture  produces  better 
direct  writing  with  some  persons.  \Yhen  the  eyes  are 
shut,  the  same  may  happen  through  preponderance  of 
visual  memory.  In  most  persons,  however,  the  move- 
ment sense  predominates  and  the  results  are  as  in 
Fig.  174. 

Some  experiments,  not  extended  far  enough  to 
enable  me  to  put  the  law  in  a  quantitative  state- 
ment, seem  to  indicate  its  general  form  as  follows: 
The  average  change  produced  by  cross-memory  is 
composed  of  two  parts,  that  due  to  the  crossing  and 
that  due  to  the  interval  of  time ;  the  average  uncer- 
tainty is  always  much  greater  than  in  memory 
without  crossing  and  increases  much  more  rapidly. 

The  method  used  in  these  experiments  was  the  same 
as  that  used  on  page  20-i.  The  original  line  was 
drawn  with  one  hand,  and  was  repeated  with  the 
other,  alternately  symmetrical  and  direct.  In  the 
particular  set  of  experiments  referred  to  the  results 
were  as  follows :  The  remembered  line  was,  on  an 
average,  sixteen  per  cent,  shorter  in  the  symmetrical 
movement    and  P 

twenty-four        per                               ^ 
cent,  shorter  in  the                          < —  ^ 

direct     movement.      ,        — ^ L 

J.  ne      average      Ull-  Fig.  its. — 3Ieasurements  on  symmetrical  and 
certainty    was    nine  Direct  Cross-memory. 

per  cent.  in.  the  symmetrical  and  nine  per  cent,  in  the 
direct. 


2o8        Thinking,  Feeling,  Doing 


These  results  can  be  indicated  as  in  Fig.  175.  The 
top  line  is  the  standard,  drawn  by  the  right  hand  in 
the  direction  of  the  arrow.  The  two  other  lines  are 
averages  of  those  by  the  left  hand;  the  portions  in 
dashes  indicate  the  regions  within  which  these  lines 
ended.  The  irregularity  is  the  same  for  both,  but 
although  both  movements  differ  from  the  standard, 
the  unsymmetrical  one  is  the  less  correct  of  the  two. 

Memory  for  tones  can  be  measured  in  a  similar  way 
to  that  employed  on  pages  107  and  108,  in  determining 
the  least  noticeable  difference.  In  fact,  all  the  experi- 
ments on  the  least  noticeable  difference  might  be 
considered  as  experiments  on  memory  with  a  very 
small  interval  of  time  between  the  two  impressions 
compared.  There  we  used  an  interval  of  two  seconds  ; 
by  changing  this  interval  to  five  secoads,  ten  seconds, 
etc.,  we  get  the  record  of  the  size  of  the  least  notice- 
able difference  as  depending  on  the  lapse  of  time. 
The  matter  is  so  simple  that  further  explanations 
hardly  seem  necessary.  A  valuable  set  of  experi- 
ments might  be  performed  with  the  tone- tester, 
described  on  page  110. 

The  method  of 
percentages  of  cor- 
rect answers  may 
also  be  employed. 
The  experiments 
described  on  page 
112,  are  to  be  re- 
peated with  differ- 
ent intervals. 

The  results  of  an  investigation  of  this  kind  are  shown 


yrnT-ir  h  n  *       i»  — ir 

Fig.  176.— Law  of  Forgetting  Tones. 


Memory  209 

in  Fig.  176.  Here  the  figures  on  the  horizontal  line 
indicate  the  number  of  seconds  that  elapsed  between 
two  tones  to  be  compared,  and  those  on  the  vertical 
line  indicate  the  percentages  of  right  answers. 

It  is  seen  that  the  maximum  certainty  is  reached  at 
two  seconds.  Thereafter  it  decreases.  At  an  interval 
of  sixty  seconds  the  uncertainty  is  so  great  that  the 
answers  are  nearly  half  right  and  half  wrong  ;  since 
mere  chance  would  make  them  half  right,  the  uncer- 
tainty is  almost  complete. 

This  is  a  characteristic  case  for  most  unmusical 
persons.  Individuals  differ,  of  course.  There  are 
intelligent  persons  who  cannot  recognise  a  tone  re- 
peated twice  in  close  succession.  On  the  other  hand, 
we  find  Mozart  and  later  piano-players  who  can  carry 
in  mind  the  slightest  differences.  Probably  the  most 
accurate  tone-memory  on  record  is  that  of  Mozart. 
Two  days  after  playing  on  a  friend's  "butter-fiddle" 
(as  he  called  it  on  account  of  its  soft  tone),  the  seven- 
year-old  Mozart,  while  playing  on  his  own  violin, 
remarked  that  the  butter-fiddle  was  tuned  to  half  of  a 
quarter  of  a  tone  lower  than  his  own.  And  this  was 
found  to  be  the  case. 

We  might  make  similar  experiments  on  touch, 
temperature,  smell,  etc.  In  fact,  memory  is  no  real 
process ;  it  is  merely  a  way  of  considering  and  com- 
paring two  impressions  at  different  times.  This  is 
what  we  did  with  a  small  interval  on  many  occasions 
in  the  earlier  chapters  of  this  book.  When  the 
interval  is  so  small  as  to  be  negligible  we  speak  of 
simultaneous  impressions. 

Numerous  sets  of  calculations  of  the  number  of 
14 


2IO         Thinking,  Feeling,  Doing 

letters  or  words  forgotten  out  of  the  total  number 
seen,  heard,  spoken,  etc.,  have  been  undertaken. 
Letters  and  words  are  very  complicated  affairs,  and  the 
results  will  vary  completely  by  a  slight  change  in  the 
word,  in  the  arrangement,  in  the  time,  in  the  loudness 
or  illumination,  in  the  intonation  or  the  size,  etc.,  etc. 
The  sources  of  error  are  so  great  that  a  scientist,  i.  e, 
a  careful  worker,  must  spend  years  of  .labour  in 
getting  them  under  control.  The  first  carefully  exe- 
cuted experiments  in  this  line  show  that  when  a  set  of 
meaningless  syllables  has  once  been  learned,  the  time 
required  for  learning  them  on  a  second  occasion  in- 
creases as  the  interval  between  the  two  occasions, 
according  to  a  definite  law. 

This  law  runs  in  the  way  shown  in  a  specimen  table 
of  results  : 

Interval  ..     0.3     1     8.8     24     48     144     744  hours 

Per  cent,  of 
work  re- 
quired for 
r  el  earning 

At  first  there  is  a  rapid  loss,  more  than  half  during 
the  first  hour  ;  then  the  loss  is  steadily  less  rapid  and 
finally  becomes  almost  constant.  Between  the  second 
day  and  the  thirty-first  day  there  is  almost  no  change. 

Further  experiments  with  letters  under  various  con- 
ditions of  rate,  repetition,  lapse  of  time,  rhythm,  etc., 
have  been  in  progress  for  many  years,  but  the  final 
results  have  not  been  reached. 

The  education  of  the  memory  powers  has  ever  been 
a  subject  of  interest  to  practical  people.  More  or  less 
fabulous  accounts  of   the   prodigies  of  memory  may 


42    56   67     66    72      75      79 


Memory 


21  I 


be  found  in  various  psychological  story-books.  Even 
when  the  records  of  the  results  to  be  obtained  are 
to  be  credited,  the  accounts  of  how  the  freaks  edu- 
cated their  memories  are  mostly  to  be  regarded  as  un- 
conscious fiction.  For  practical  purposes  statements  on 
the  development  of  memory  should  be  founded  on  ob- 
servation of  and  experiment  on  ordinary  people. 

The  fundamental  lawS  for  the  cultivation  of  memory 
are :  intensifying  the  image  by  attention,  and  keeping 
it  ready  by  conscious  repetition. 

In  the  first  place,  intensify  the  impression.  See, 
hear,  do  what  you  wish  to  remember.  You  cannot 
expect  to  remember  a  picture  when  you  have  not 
really  seen  it.  It  is  said  that  the  Niirnbergers  never 
hang  a  man  till  they  have  caught  hitn,  and  yet  many 
a  teacher  expects  his  pupils  to  remember  a  lesson 
without  really  learning  it. 

How  shall  we  intensify  the  impression?  Any 
method  that  increases  the  amount  of  attention  will  help 
to  intensify  the  impression ;  these  methods  have  been 
considered  in  Chapter  XVII.  But  it  is  not  sufficient 
merely  to  pay  attention;  something  further  must  be 
done  if  the  impression  is  to  be  retained.  No  experi- 
mental work  in  the  laboratory  has  been  done  on  this 
problem,  but  some  of  the  most  energetic  experimenting 
has  been  carried  on  by  advertisers  on  account  of  the 
business  interests  involved.  The  very  principles  they 
have  discovered  are  just  the  ones  we  should  make 
use  of  on  ourselves    and    in    teaching  others. 

A  powerful  principle  employed  for  memorising  a 
fact  is  that  of  the  ridiculous.  You  cannot  forget 
the   absurd  pictures  by   means    of   which  publishers 


212         Thinking,  Feeling,  Doing 

and  players  advertise  their  new  wares;  or  the  musi- 
cian's hair,  whose  echoes  last  longer  than  those  of 
his  playing. 

A  subordinate  principle  belonging  to  the  ridiculous 
is  that  of  the  pun.  A  good  pun  is  an  aesthetically 
ridiculous  contradiction ;  a  bad  one  is  intensely  irri- 
tating but  is  ridiculous  ridiculousness.  If  you  wish 
your  class  to  remember  the  story  of  Waterloo,  make 
a  pun  about  it,  and  a  bad  one,  too.  (You  all  know 
the  horrid  one  to  which  I  refer.) 

A  second  principle  of  memorising  is  that  of  rhyme. 
We  all  know  how  much  easier  it  is  to  learn  rhymed 
poetry  than  blank  verse  or  prose.  Rhymed  couplets 
or  verses  can  frequently  be  employed  to  memorise 
difficult  facts.  The  farmer's  calendars  in  olden  times 
were  based  on  the  memorial  days  of  the  saints.  To  re- 
member when  the  sowing,  reaping,  etc.,  should  be 
done,  an  appropriate  couplet  was  rhymed  with  the  day. 
The  same  method  is  employed  in  some  aids  to  learning 
history.  Those  who  have  studied  formal  logic  will 
remember  the  mediaeval  memory-verse  beginning, 
*'  Barbara,  Celarent,"  etc. 

The  principle  of  rhyme  when  combined  with  the 
ridiculous  can  be  carried  so  far  that  couplets  and 
stanzas  cannot  be  forgotten.  Those  who  have  read 
Mark  Twain's  story  about  "Punch,  Brothers,"  etc., 
will  remember  a  case. 

The  principle  of  alliteration,  i.  e.,  of  words  beginning 
with  the  same  sound,  was  largely  used  in  olden 
poetry.  Memory  was  doubtless  greatly  assisted 
thereby.  It  is  in  use  to  a  certain  extent  to-day  in 
book-titles,   catch-words,  advertisements,  etc. 


Memory  2 1 3 

Another  very  efficient  principle  is  that  of  the  puzzle. 
Dissected  maps,  the  game  of  authors,  the  solution  of 
mathematical  conundrums,  are  cases. 

To  retain  things  in  memory  they  should  generally  be 
repeated  a  number  of  times.  With  a  very  intense  first 
impression  the  repetition  may  be  unnecessary ;  with 
weak  impressions  it  may  be  required  frequently.  The 
relation  of  intensity  to  repetition  has,  however,  never 
been  experimentally  determined. 

The  fundamental  fact  to  be  observed  is  that  the  repe- 
tition must  be  conscious.  Nearly  everybody  supposes 
that  a  series  of  facts,  a  group  of  names,  a  collection  of 
dates,  can  be  learned  by  simple  mechanical  repetition. 
But  in  "learning  by  rote"  we  soon  cease  to  think  of 
what  we  are  saying.  Yet  we  remember  the  connec- 
tion between  two  words  only  when  we  pay  attention 
to  the  fact  of  such  connection.  For  example,  suppose 
we  wish  to  remember  that  Aristotle  was  a  tutor  to 
Alexander.  The  fact  strikes  us  at  once  and  will  have 
some  power  of  persistence  in  our  memories.  Any 
amount  of  mechanical  repetition  of  "  Aristotle-teach- 
Alexander "  will  not  assist.  But  if  each  repetition 
be  a  conscious,  attentive  connection  of  the  three  facts, 
there  is  a  distinct  gain.  The  difficulty  lies  in  making 
the  repetition  conscious  and  not  mechanical. 

The  methods  of  doing  this  may  be  described  as 
direct  and  mediate.  In  the  direct  method  the  indi- 
vidual calls  up  each  time  by  an  effort  of  will  a  char- 
acteristic picture  of  Aristotle  teaching  Alexander. 

The  mediate  method  consists  in  finding  some  word 
naturally  connected  with  Aristotle  which  by  another 
natural  connection  brings  up  another  word  and  so   on 


2  14        Thinking,  Feeling,  Doing 

till  "  teach  "  is  reached,  after  which  the  same  process 
stretches  from  "teach"  to  "  Alexander."  For  exam- 
ple, we  may  make  the  following  series  of  connections : 

Aristotle — aristocracy  teach  a  class — teach  a  lass 

aristocracy — better  class  alas! — alack! 

better  class — teach  a  class  alack! — Aleck 

teach  a  class — teach  Aleck — Alexander 

Again  suppose  we  wish  to  remember  that  the  car 
with  a  red  light  goes  to  Westville.  We  may  con- 
struct the  associations  : 

red — sunset 

sun  sets  in  the  west 

west — Westville 

In  selecting  the  connecting  links  we  choose  those 
that  are  most  striking.  It  is  convenient  to  look  for 
similarities  of  sound  (all  of  those  used  for  Aristotle — 
teach — Alexander  except  one  are  of  this  sort)  or  of 
meaning  (aristocracy — better  class),  or  for  contrasts, 
or  for  modifiers  of  color  (red — sunset),  size,  place  (in 
the  west),  quality,  quantity,  etc,  or  for  activities,  etc- 
(sun — sun  sets). 

Two  important  principles  are  involved  in  this 
method  of  memorising.  The  first  is  that  of  forcing 
attention  to  the  things  to  be  remembered.  Thus,  in 
searching  for  a  word  to  connect  with  "Aristotle,"  we 
are  obliged  to  think  of  the  name  intently  and  often. 
When  we  have  found  "aristocracy,"  we  are  forced  to 
think  of  it  in  its  connection.  The  harder  we  have  to 
search  for  connecting  links,  the  more  we  are  forced  to 
attend  to  the  words.  This  principle  of  forced  attention 
is,  in  fact,  the  object  of  the  method. 


Memory 


215 


The  objection  made  to  such  associative  systems  is  that 
they  are  too  cumbersome  when  anything  is  to  be  re- 
called. While  practising  with  one  of  these  systems  I 
noticed  the  tendency  of  the  middle  links  to  fall  out; 
no  matter  how  many  intermediate  words  were  inserted 
between  "Aristotle"  and  "teach,"  after  awhile  the 
two  were  involuntarily  associated,  with  no  thought  of 
the  middle  links.  This  principle,  which  is  in  harmony 
with  facts  previously  discovered  concerning  the  asso- 
ciation of  ideas,  1  might  be  called  the  obliteration  of 
intermediate  associations. 

Like  all  our  men- 
tal life,  memory 
depends  upon  age. 
In  a  series  of  exper- 
iments on  school 
children  a  tone  was 
sounded  for  two 
seconds,  then  it  was 
started  again  and 
the  child  was  re- 
quired to  stop  it 
when  it  had  lasted 
as  long  as  before- 
In  all  cases  the  sec- 
ond sound  was 
made  too  short ;  the 
younger  children 
often  made  the  sound  by  memory  only  one  fourth  of 

1  The  original  experiments  on  mediate  association  of  ideas 
are  reported  in  my  New  Psychology,  Ch.  XIII. 


TTME  MEUOKY. 


BOVS  ANBOKLi 

SOYi 

£!RLS 

ARUHMETItUJtEAll 


Fig.  177 — Dependence  of  Time-memory  on  Age, 


2i6         Thinking,  Feeling,  Doing 

its  true  length.    As  they  grew  older,  the  memory  be- 
came more  accurate. 

Concerning  the  ages  above  seventeen  no  experiments 
have  been  made.  We  know,  however,  that  old  people 
gradually  lose  their  memories.  Indeed,  we  might  say 
that  memory  is  the  ostensible  friend  who  insists  upon 
presenting  us  with  a  house  bountifully  furnished  with 
the  skeletons  of  past  sins,  but  who  in  old  age  turns  us 
out  into  the  cold  night  of  forgetfulness  when  we  would 
gladly  remember  even  the  sins. 


CHAPTER  XIX 

SUGGESTION    AND    EXPECTATION 

IN  his   memoirs    Robert-Houdin  begins  with  a  de- 
scription of  the  effects  of  suggestion  from  the  time 
of  day : 

"  Eight  o'clock  has  just  struck  :  my  wife  and  children 
are  by  my  side.  I  have  spent  one  of  those  pleasant 
days  which  tranquillity,  work,  and  study  can  alone  se- 
cure— with  no  regret  for  the  past,  with  no  fear  for  the 
future,  I  am — I  am  not  afraid  to  say  it — as  happy  as 
man  can  be. 

"And  yet,  at  each  vibration  of  this  mysterious  hour, 
my  pulse  starts,  my  temples  throb,  and  I  can  scarce 
breathe,  so  much  do  I  feel  the  want  of  air  and  motion. 
I  can  reply  to  no  questions,  so  thoroughly  am  I  lost  in 
a  strange  and  delirious  reverie. 

"  Shall  I  confess  to  you,  reader  ?  And  why  not?  for 
this  electrical  effect  is  not  of  a  nature  to  be  easily  un- 
derstood by  you.  The  reason  for  my  emotion  being 
extreme  at  this  moment  is  that,  during  my  professional 
career,  eight  o'clock  was  the  moment  when  I  must  ap- 
pear before  the  public.  Then,  with  my  eye  eagerly 
fixed  on  the  hole  in  the  curtain,  I  surveyed  with  intense 
pleasure  the  crowd  that  flocked  to  see  me.  Then,  as 
now,  my  heart  beat,  for  I  was  proud  and  happy  at  such 
success. 

217 


2i8      Suggestion  and  Expectation 


"Do  you  now  understand,  reader,  all  the  reminis- 
cences this  hour  evokes  in  me,  and  the  solemn  feeling 
that  continually  occurs  to  me  when  the  clock  strikes  ?  " 

Some  years  ago  I  began  experiments  on  the  power  of 
suggestion  to  produce  hallucinations  and  illusions. 
One  of  the  first  arrangements  is  shown  in  Fig.  178.  It 
consists  of  a  plunge 
battery  which  sends 
a  current  through 
a  resistance  -  wire 
whenever  the  cir- 
cuit is  completed 
by  bringing  the 
ends  together  in 
the  hand  of  the  ex- 
perimenter. The 
person  experiment- 
ed upon  takes  the 
resistance-wire  be- 
tween his  fingers  ; 
the  experimenter,  holding  his  hand  out  of  sight,  brings 
the  ends  of  the  circuit  together  and  sets  the  battery  in 
action  by  shoving  down  the  plunger.  The  person  ex- 
perimented upon  feels  the  wire  become  slightly  warm 
after  a  few  moments.  The  experiment  is  repeated  a 
few  times.  After  that  the  experimenter  breaks  the 
circuit  by  opening  his  hand  unknown  to  the  subject. 
The  plunger  is  put  down  as  before,  and  the  unsuspect- 
ing person  experimented  upon  inevitably  feels  the 
wire  become  warm,  although  it  really  does  not  do  so. 

This  method  has  been  extended  to  include  lights, 


Fig.  178. — Producing  a  Hallucination  of 
Warmth. 


Suggestion  and  Expectation      219 

tones,  and  actual  objects.  Thus  a  person  was  to  press 
a  key  as  soon  as  he  could  hear  a  faint  tone  in  a  tele- 
phone, which  would  be  produced  a  moment  after  he 
had  received  a  signal  to  be  ready.  The  faint  tone  was 
actually  produced  a  few  times,  but  after  that  it  was 
sufficient  to  giye  the  signal  only  ;  he  would  regularly 
hear  the  tone  again  purely  as  a  matter  of  suggestion. 
In  another  set  of  experiments  a  small  blue  bead  was 
placed  inside  of  the  white  circle  shown  through  the 
door  in  Fig.  16.  A  tape  measure  was  stretched  from 
the  door  to  a  distant  point.  The  person  experimented 
upon  was  told  to  start  at  a  distant  point  and  walk 
toward  the  door  until  he  could  first  distinguish  the 
bead  ;  he  was  then  to  read  off  on  the  tape  measure  just 
how  far  he  was  from  the  door.  This  he  continued  to 
do  a  number  of  times,  the  distance  being  noted  each 
time.  After  the  first  few  times  the  bead  was  slipped 
out  of  sight  unknown  to  him  ;  this  made  no  difference, 
and  he  continued  to  see  it  and  read  off  the  distance  as 
before.  These  two  experiments  were  tried  on  a  large 
number  of  persons  and  never  failed. 

Experiments  in 
measuring  the  ef- 
fects of  suggestion 
of  size  can  be  made 

O/^  ^^^  /=S  ^^^  ^^=^  /=^  ^^  aseries  of  round 
Vj  (^  (^  (^  Vj  (^  blocks     painted 
\5      20     25      30      3S      ^0      ^s    black;    in   appear- 


50       65       60       65      70       75      80     3^^^^     ^1^^^®'    ^^^   i^ 

weight  they  are  dif- 
ferent The  block  D 


Fig.  179.— Blocks  for  Measuring  the  Effect  of     weight  they  are  dif- 
a  Suggestion  of  Size. 


220         Thinking,  Feeling,  Doing 

is  a  very  big  block  ;  you  are  to  pick  out  that 
one  of  the  series  which  appears  of  the  same  weight 
as  the  big  one,  when  lifted  between  thumb  and 
finger.  You  know  nothing  about  the  blocks  except 
that,  to  the  best  of  your  belief,  the  big  one  is  of  the 
same  weight  as  the  medium-sized  one  picked  out.  You 
put  them  on  the  scales  ;  down  goes  the  big  one ;  you 
judged  it  to  be  much  lighter  than  it  was.  You  try  it  over 
again  as  often  as  you  please  ;  always  the  same  result. 
By  means  of  the  scales  you  find  the  medium  one  that 
w^eighs  exactly  the  same  as  the  large  one.  Then  you 
compare  them  by  lifting  ;  nothing  but  the  incontestable 
evidence  of  the  scales  will  make  you  believe  they  are  the 
same.  Af  terbeingfamiliarwith  the  experiment  for  many 
years  I  still  find  the  effect  almost  as  strong  as  at  first. 

But  how  much?  It  is  not  sufficient  to  show  that 
there  is  a  suggestive  effect,  you  must  measure  it.  The 
difference  in  weight  between  the  two  blocks  supposed 
to  be  equal  gives  the  effect  of  suggestion  in  just  so 
many  ounces  or  grams. 

In  a  set  of  experiments  carried  out  on  school  child- 
ren the  medium-sized  blocks  were  graded  in  weight 
from  15  grams  to  80  grams.  A  large  block  D  and  a 
small  block  c/,  each  of  55  grams,  were  successively  com- 
pared with  the  set  of  graded  blocks.  The  difference 
between  the  weight  picked  out  for  the  larger  one,  e.  g.^ 
20  grams,  and  that  for  the  smaller  one,  e.  g.,  70  grams, 
would  give  the  effect  of  the  difference  in  size  between 
the  two  blocks.  The  difference  in  weight  in  this  ex- 
ample would  be  50  grams,  which  would  be  the  result 
of  the  difference  of  six  centimetres  in  the  diameter  of 
the  blocks. 


Suggestion  and  Expectation       221 

The  effect  of  the  suggestion  depends  upon  the  age. 
The  results  for  the  New  Haven  school  children  are 
indicated  in  Fig.  180.  The  figures  at  the  bottom  indi- 
cate the  ages ;  those  at  the  left  the  number  of  grams 
in  the  effect  of  suggestion. 

About  100  children  of  each  as^e  from  6  to  17  were 
taken.  The  average  effect  of  the  suggestion  was  as 
follows  :  6  years,  42  grams ;  7  years,  45  grams  ;  8 
years,  48  grams  ;  9  years,  50  grams  ;  10  years,  44  grams  ; 
11  and  12  years,  40  grams ;  13  years,  38  grams  ;  14  to 
16  years,  35  grams ;  17  years,  27  grams.  For  all  ages 


. OiRKS. 


2; — 7 7 7 7i 7? 73 73 77 73= /t /;> 

Fig.  180. — Dependence  of  the  Efifect  of  Suggestion  on  Age  and  Sex. 

the  average  was  above  twenty-five  grams.  The  sug- 
gestibility slowly  increased  from  six  years  to  nine  years; 
after  nine  years  it  steadily  decreased  as  the  children 
grow  older.  The  results,  when  separately  calculated 
for  boys  and  girls,  showed  that  at  all  ages  the  girls  were 
more  susceptible  to  suggestion  than  the  boys,  with  the 
exception  of  the  age  nine,  where  both  were  extremely 
susceptible. 

These  are  the  average  results   for  large  numbers 
of  children.     Many  young  people,  however,  were  so 


222       Thinking,  Feeling,  Doing 

susceptible  that  the  set  of  middle-sized  blocks  did  not 
range  far  enough  to  suit  them.  At  the  age  of  seven 
years  37  per  cent,  of  the  children  declared  that  the  large 
block  was  lighter  than  the  lightest  block,  and  that  the 
small  block  was  heavier  than  the  heaviest.  The  act- 
ual difference  between  them  was  65  grams ;  thus  the 
effect  of  suggestion  was  more  than  the  weight  of  the 
suggesting  blocks  D  and  d. 

The  factors  that  produce  such  a  deception  of  judg- 
ment seem  to  consist  in  a  suggestion— or,  rather,  a  dis- 
appointed suggestion — of  weight.  Big  things  are,  of 
course,  heavier  than  little  things  of  exactly  the  same 
kind.  When  we  find  two  things  of  the  same  appear- 
ance but  differing  in  size,  the  big  thing  musthe  heav- 
ier. This  reasoning  is  all  done  without  our  suspecting 
it,  and  we  unconsciously  allow  our  judgment  of  weight 
to  be  influenced  by  the  size  as  seen.  When  the  eyes 
are  closed  and  the  blocks  are  lifted  by  strings,  of 
course  there  is  no  illusion. 

Which  is  the  heavier,  a  pound  of  lead  or  a  pound  of 
feathers  ?  A  pound  of  lead,  says  the  unsuspecting  per- 
son, and  then  you  guy  him  for  his  stupidity.  But  this 
poor  fellow,  who  has  been  laughed  at  for  centuries,  is 
right.  A  pound  is  n't  a  pound  all  the  world  over  ;  it 
all  depends  how  the  pound  looks.  A  pound  of  lead  is 
heavier  than  a  pound  of  feathers.  Try  it  with  a  pil- 
low and  a  piece  of  lead  pipe.  No  matter  if  the  scales 
do  say  that  they  weigh  just  the  same,  the  pound  of 
lead  is  much  the  heavier  as  long  as  you  look  at  it 

In  the  preceding  case  we  have  had  a  suggestion  from 
sight  alone.  Similar  effects  are  produced  by  differ- 
ences in  the  span  of  the  fingers.     Suppose  we  have  all 


Suggestion  and  Expectation      223 

our  blocks  of  exactly  the  same  diameter.  We  have 
one  set  just  alike  in  size  but  differing  in  weight,  and 
other  blocks  of  just  the  same  diameter  and  weight  but 
differing  in  length,  one  being  very  long  and  the  other 
very  short.  The  experiments  are  made  in  the  same 
way  as  before  except  that  the  eyes  are  closed.  The 
suggestion  arises  from  the  difference  in  span  of  the 
fiDgers  for  a  long  block  and  a  short  one.  By  looking 
at  the  blocks  with  the  eyes  open,  a  sight-suggestion 
is  added  to  the  muscular  suggestion.' 

In  the  preceding  cases  it  has  been  noticed  how  a  sug- 
gestion causes  a  change  in  judgment;  there  is  another 
field  in  which  suggestion  is  very  active,  namely,  the 
suggestion  of  movement.  While  a  person  is  exerting 
his  whole  power  on  a  dynamometer  (page  69),  let  him 
observe  contracting  movements  of  your  hand.  He  soon 
feels  irresistible  twitchings  in  his  own  hand  and  actually 
exerts  still  more  force. 

The  suggestion  of  movement  may  even  take  effect 
against  the  will  of  the  person  concerned.  A  child 
in  school  with  the  Vitus  dance  will  sometimes  be  in- 
voluntarily imitated  by  the  others.  A  contagion  of 
this  kind  that  occurs  in  every-day  life  is  the  effect  of 
gaping. 

The  orator  and  the  actor  make  use  of  facial  expressions 
and  gestures  intended  to  arouse  similar  impulses  in 
their  hearers  and  consequently  to  make  their  ideas 
more  effective. 

On  the  other  hand,  if  you  wish  to  get  the  thoughts  of 
the  person  with  whom  you  are  speaking,  you  should 

^  Further  researches  on  the  size-weight  illusion  are  described 
in  my  New  Psychology,  Ch.  XIX. 


224        Thinking,  Feeling,  Doing 

look  steadily  at  his  face.  Ilis  expression  cannot  help 
changing,  and  these  changes  tend  to  produce  similar 
changes  in  your  own  face,  thereby  awakening  various 
emotions  of  doubt,  confidence,  anxiety,  etc.  The 
readiness  of  women  to  read  characters  in  this  way  may 
be  due  to  their  greater  susceptibility  to  suggestion. 

Every  idea  of  a  movement  brings  an  impulse  to  move- 
ment. This  is  especially  prominent  in  the  many  indi- 
viduals who  cannot  keep  a  secret  The  very  reading 
and  thinking  about  crimes  and  scandalous  action  pro- 
duce a  tendency  to  commit  them.  In  some  persons 
this  influence  is  quite  irresistible.  As  soon  as  one 
bomb-thrower  attacks  a  rich  banker,  everybody  knows 
that  in  a  week  half  a  dozen  others  will  do  the  same.  No 
sooner  does  one  person  commit  suicide  in  such  a  way 
that  it  is  strikingly  described  in  the  newspapers,  than 
a  dozen  others  go  and  do  likewise. 

A  runner,  prepared  to  start,  can  often  cause  the 
starter  to  fire  his  pistol  unintentionally  by  starting  to 
run.  This  runner  is  ahead  of  the  starter  by  the  amount 
of  the  starter's  reaction-time,  while  the  other  runners 
are  behind  the  starter  by  the  amounts  of  their  own 
reaction-times.  As  the  reaction-time  may  readily 
amount  to  one-third  of  a  second,  the  runner  who  relied 
on  the  suggestion  may  gain  by  a  large  fraction  of  a 
second. 

The  full  significance  of  suggestibility  is  apparent 
when  we  remember  that  teaching,  preaching, 
acting,  public  speaking,  and  pleading  are  forms  of 
suggesting.  The  freaks  of  hypnotism  are  performed 
by  suggestion.  The  faith-cures  and  the  miraculous 
effects  of  the  Grotto  of  Lourdes  are  benevolent  sugges- 


Suggestion  and  Expectation       225 

tions.  The  ceremonials  of  our  churches  are  suggestions 
bringing  us  into  a  religious  frame  of  mind.  The  ma- 
nipulations of  the  spiritualists  and  the  monotonous 
blackness  of  a  funeral  are  all  forms  of  su2:2:estion. 
How  shall  we  develop  the  children  so  as  to  produce  in 
them  minds  well-balanced  in  respect  to  suggestion  ?  Is 
this  not  as  important  a  task  as  learning  to  do  percentage 
or  to  parse  a  sentence  ?     The  problem  is  still  unsolved. 

In  expecting  an  event  we  have  some  thought  in 
mind  ;  this  thought  often  acts  as  a  suggestion. 

The  time  of  reaction  depends  on  its  expectedness ; 
unexpected  events  require  in  general  more  time  and 
produce  very  irregular  results.  It  is  customary  to  give 
a  warning  click  about  two  seconds  before  an  experi- 
ment. Experiments  on  one  person  gave  an  average 
reaction-time  of  81^  without  warning  and  19-S  with 
warning  (see  Chapter  III). 

It  also  makes  a  difference  if  the  attention  is  directed 
to  the  stimulus  expected  or  to  the  movement  to  be  exe- 
cuted. In  general  the  latter  method  is  quicker,  but 
with  some  persons  the  reverse  is  the  case.  Experi- 
ments made  on  one  subject  give  as  reaction-time  to 
sound  the  result  22^  when  the  attention  was  directed 
toward  the  expected  sound,  and  13^  when  it  was 
directed  toward  the  finger  to  be  moved. 

The  expectation  that  a  star  will  pass  one  of  the  hair- 
lines in  a  telescope  produces  differences  in  regard 
to  the  record  of  the  time  of  its  passage  as  actually  re- 
corded. This  phenomenon,  which  led  to  the  discov- 
ery of  mental  times,  is  more  complicated  than  the 
simple  cases  of  reaction-time  and  thinking-time  that 
we  have  considered  in  Chapters  III  and  IV. 


226         Thinking,  Feeling,  Doing 

Let  me  illustrate  by  a  simple  case  how  this  happens. 
Suppose  that  we  have  to  determine  the  time  of  the  pas- 
sage of  a  star  at  some  distance  from  the  pole  across 
the  meridian.  We  may  employ  an  old  astronomical 
method  which  is  still  sometimes  used  for  time-determi- 
nations, and  which  is  called  the  "  eye  and  ear  method." 
A  little  before  the  time  of  the  expected  passage,  the 
astronomer  sets  his  telescope,  in  the  eye-piece  of  which 
there  have  been  fixed  a  number  of  clearly  visible  ver- 
tical threads,  in  such  a  way  that  the  middle  thread  ex- 
actly coincides  with  the  meridian  of  the  part  of  the  sky 
under  observation.  Before  looking  through  the  in- 
strument, he  notes  the  time  by  the  astronomical  clock 
at  his  side,  and  then  goes  on  counting  the  pendu- 
lum-beats while  he  follows  the  movement  of  the 
star. 

Now,  the  time-determination  would  be  very  simple  if 
a  pendulum-beat  came  at  the  precise  moment  at  which 
the  star  crosses  the  middle  thread.  But  that,  of  course, 
happens  only  occasionally  and  by  chance ;  as  a  rule, 
the  passage  occurs  in  the  interval  between  two  beats. 
To  ascertain  the  exact  time  of  the  passage,  therefore,  it 
is  necessary  to  determine  how  much  time  has  elapsed 
between  the  last  beat  before  the  passage  and  the  pas- 
sage itself,  and  to  add  this  time — some  fraction  of  a 
second — to  the  time  of  the  last  beat.  The  observer 
notes,  therefore,  the  position  of  the  star  at  the  beat 
directly  before  its  passage  across  the  middle  thread,  and 
also  its  position  at  the  beat  which  comes  immediately 
after  the  passage,  and  then  divides  the  time  according 
to  the  length  of  space  traversed. 

If /(Fig.  181)  is  the  middle  thread  of  the  telescope, 


Suggestion  and  Expectation      227 

a  the  position  of  the  star  at  the  first  beat,  and  h  at  the 
second,  and  if  af  is^  twice  as  long  as  /6,  then  f  of  a 


a  f  b 

Fig.  181. — Actual  Positions  of  the  Star  at  the  Pendulum-beats. 

second  must  be  added  to  the  last  counted  second. 

It  has  already  been  told  (page  27)  how  astrono- 
mers disagree  in  their  records  although  the  star  had 
exactly  the  same  position  for  all.  A  constant  and  regu- 
lar difference,  such  as  this  actually  is,  can  be  explained 
on  the  assumption  that  the  objective  times  of  the  actual 
events  and  the  times  of  their  notice  by  the  observer  are 
not  identical,  and  that  these  times  show  further  dif- 
ferences from  one  another  according  to  the  individual 
observer.  Now,  attention  will  obviously  exercise  a 
decisive  influence  upon  the  direction  and  magnitude 
of  such  individual  variations.  Suppose  that  one 
observer  is  attending  more  closely  to  the  visual  im- 
pression of   the   star.     A  relatively  longer  time  will 

*       I       •         * 

a  c         f        b  d 

Fig.  182.— Supposed  Positions  with  Visual  Attention. 

elapse  before  he  notices  the  sound  of  the  pendulum- 
beat.  If,  tlierefore,  the  real  position  of  the  star  is  a 
at  the  first  beat  and  b  at  the  second  (Fig.  182)  the 
sound  will  possibly  not  be  noticed  till  c  and  d,  so 
that  these  appear  to  be  the  two  positions  of  the  star. 
If  ac  and  bd  are  each  of  them  -J  of  a  second,  the  pass- 
age of  the  star  is  plainly  put  -|  of  a  second  later  than 
it  really  should  be. 


228        Thinking,  Feeling,  Doing 

On  the  other  hand,  if  the  attention  is  concentrated 
principally  on  the  pendulum-beats,  it  will  be  fully 
ready  and  properly  adjusted  for  these,  coming  as  they 
do  in  regular  succession,  before  they  actually  enter 
consciousness. 

Hence  it  may  happen  that  the  beat  of  the  pendulum 
is  associated  with  some  point  of  time  earlier  than  the 
exact  moment  of  the  star's  passage  across  the  meridian. 


*    .  I  *    * 

c    a  f    d     b 

Fig.  183.— Supposed  Positions  with  Auditory  Attention. 


In  this  case  you  hear  too  early,  so  to  speak,  just  as  in 
tlie  other  case  you  heard  too  late.  The  positions  c  and 
d  (Fig.  183)  are  now  inversely  related  to  a  and  h.  If 
ca  and  db  are,  say,  f  of  a  second,  the  passage  is  put  f  of 
a  second  earlier  than  it  really  occurs.  If  we  imagine 
that  one  of  two  astronomers  observes  on  the  scheme  of 
Fig.  182,  the  other  on  that  of  Fig.  183— in  other 
words,  that  the  attention  of  the  one  is  predominantly 
visual,  that  of  the  other  predominantly  auditory — there 
will  be  a  constant  personal  difference  between  them 
*^^  i  "h  f  =  -f  <^f  ^  second  You  can  also  see  that 
smaller  differences  will  appear  where  the  manner  of 
observing  is  the  same  in  both  cases  but  with  differences 
in  the  degree  of  the  strain  of  the  attention ;  while  larger 
differences  must  point  to  differences  like  those  just 
described,  in  the  direction  of  the  attention. 


CHAPTER  XX 

GENERAL    PROBLEMS 

HAVING  become  familiar  with  some  of  the  methods 
and  results  of  psychological  work,  we  are  now 
in  a  position  to  discuss  some  of  the  more  general  pro- 
blems of  the  science.  This  is  exactly  the  opposite  of 
the  procedure  of  the  psychologist  of  the  old  school, 
who  in  the  quiet  of  his  library  began  and  ended  with 
"looking  into  his  own  mind,"  describing  what  he  saw 
there  and  speculating  on  its  fundamental  laws  and  the 
nature  of  the  soul.  This  ''arm-chair"  psychology — as 
I  have  ventured  to  term  it — was  the  only  psychology 
possible  before  the  new  methods  were  devised  ;  its 
representatives  included  some  of  the  greatest  thinkers 
the  world  has  seen — Aristotle,  Locke,  Hume,  Hamil- 
ton, etc.  But  the  very  same  method  led  other  more  or 
less  clever  men  to  views  of  the  mind  that  to-day  seem 
either  silly  or  insane.  I  need  only  mention  the  doc- 
trine of  Schelling,  that  the  contents  of  dreams  are 
truer  than  our  waking  experiences;  or  the  statements 
of  an  American  college  professor  that  through  Mrs. 
Piper,  a  hysterical  woman,  he  was  able  to  communicate 
with  the  spirit  of  his  uncle  and  thus  find  out  when 
his  little  brother  had  had  the  measles ;  or  the  delu- 
sion of  "  thought  transference,"  whose   existence  was 

229 


230         Thinking,  Feeling,  Doing 

stoutly  maintained  by  an  English  professor  in  spite  of 
the  fact  that  the  first  case  turned  out  to  be  a  swindle 
by  two  clever  little  girls,  and  also  of  the  fact  that 
no  "  thought  transference "  could  ever  be  verified  by 
a  laboratory  experiment. 

All  this  rubbish  we  can — and  must — throw  over- 
board, as  the  other  sciences  have  done,  one  after 
the  other,  ever  since  Galilei  introduced  experimental 
methods  to  replace  vague  speculation.  We  must  be- 
gin with  the  careful  collection  of  facts  by  modern 
methods.  These  methods  include  in  the  first  place 
unaided  observation  of  normal  persons ;  its  results  are 
always  so  contaminated  by  error  (pp.  2 — 8)  that  we  can 
rely  on  it  only  for  general  outlines  of  the  facts  and  for 
suggestions  for  further  work.  To  improve  observa- 
tions we  make  experiments  (p.  11),  and  are  thus 
able  to  get  uncontrovertible  records.  Nearly  every 
portion  of  mind  has  now  been  opened  up  to  experi- 
mental methods ;  even  the  feelings  have  at  last  yielded 
(Chapter  XVI).  Just  so  far  as  experiment  goes  do  we 
have  knowledge  that  can  be  relied  on  ;  where  it  has  not 
only  yet  gone — as  in  the  study  of  the  emotions — we  have 
guesswork,  and  that  is  worse  than  nothing.  When 
measurements  are  introduced  into  observations  with 
and  without  experiments,  we  have  definite  results  of 
the  most  reliable  kind. 

Clinical  observation  of  defects  of  sensation,  emotion, 
and  will,  and  of  mental  diseases  is  another  method  of 
the  highest  importance ;  it  is  often  aided  by  experi- 
ment and  measurement.  The  introduction  of  this 
method  into  psychological  work  is  quite  new ;  at  each 
advance  it  has  produced  revolutionary  results.     The 


General  Problems  231 

whole  doctrine  of  colour  sensation  (p.  126)  rests  upon  the 
study  of  defects  of  colour  vision.  Entirely  new  laws 
of  attention  and  memory  are  now  being  worked  out  by 
experiments  on  mentally  unsound  persons.  Patholog- 
ical cases  are,  indeed,  striking  experiments  performed 
by  nature  which  call  our  attention  to  unsuspected 
facts.  At  present  we  have  no  inkling  of  the  methods 
to  be  employed  in  investigating  the  emotions  and 
moods,  but  a  studv  of  their  abnormalities  amonor  the 
nervous  and  the  insane  would  soon  give  the  clues. 

We  have  to  begin,  then,  all  studies  of  mental  life 
by  the  most  careful  collection  of  facts,  arranging  exper- 
iments, measurements,  and  records  at  each  step,  and 
doubting  every  result  till  it  is  proven.  Along  with 
this  collection  of  facts  we  begin  to  formulate  general 
laws,  such  as  the  law  of  practice,  the  law  of  fatigue, 
etc.  On  the  basis  of  such  general  laws  we  can  specu- 
late, if  we  wish,  concerning  such  general  questions  as 
the  "nature  of  mind,"  "the  immortality  of  the  soul," 
etc.  Yet  these  problems  can  be  answered  only  by  be- 
lief ;  psychology — that  is,  mental  science  in  the  newer 
meaning — has  not  furnished  and  cannot  furnish  any 
facts  that  bear  upon  them. 

What  is  the  material  of  psychological  investigations  ? 
It  consists  in  the  first  place  of  my  own  sensations, 
feelings,  and  volitions.  At  the  present  moment,  for 
example,  I  am  aware  of  a  room  in  which  I  sit,  of  a  desk, 
chairs,  books,  etc.,  of  persons  in  the  room,  and  so  on. 
All  these  things  appear  to  me  as  patches  of  colour,  and 
as  forms  of  various  kinds  at  various  distances.  I  see 
that  my  hand  touches  these  patches  of  colour 
and  I  feel  that  they  have  consistency,  etc,     Some  of 


232        Thinking,  Feeling,  Doing 

these  patches  of  colour  move  independently  of  me, 
such  as  the  clock,  or  the  tuning  fork,  or  the  drum 
when  once  set  in  motion ;  these  I  use  as  registering 
apparatus  to  indicate  when  a  colour  appears  to  me  and 
when  I  make  a  responsive  movement.  In  this  way  I 
get  records  of  my  reaction-time  (p.  13)  and  thinking- 
time  (p.  37),  and  deduce  the  laws  of  my  thinking, 
feeling,  and  willing  as  far  as  concerns  time.  In  sim- 
ilar ways  I  arrange  other  apparatus — which  I  see  as 
patches  of  colour,  feel  as  heavy,  cold,  etc.,  but  which 
I  can  prove  to  act  independently  of  me — to  experi- 
ment on  my  various  sensations,  feelings,  and  emotions 
(Chapters  II  to  XVI).  Thus  one  portion  of  the  mate- 
rial of  psychological  investigation  consists  of  my  own 
mental  experience.  The  investigation  of  this  material 
has  been  called  the  "introspective  method";  we 
had  better  speak  of  the  "  introspective  material "  of 
psychology. 

Among  the  patches  of  colour  I  see  about  me  there 
are  some  that  I  consider  human  beings  like  myself.  I 
also  believe  that  they  have  sensations,  feelings,  and 
volitions  which  are  in  the  main  like  my  own.  I  apply 
my  apparatus  to  them  and  find  both  agreement  and 
disagreement  in  the  results.  As  far  as  they  agree,  1 
assume  that  these  people  have  the  same  sensations, 
feelings,  and  volitions  as  myself;  where  they  disagree, 
I  deduce  differences.  For  example,  in  sorting  wools 
in  the  test  for  colour-blindness  I  find  that  most  persons 
sort  as  I  do ;  I  therefore  conclude  that  we  see  the  col- 
ours alike.  About  four  per  cent,  however,  sort  differ- 
ently ;  half  of  them  confuse  light  greens  with  greys,  and 
half  confuse  dark  greens  with  greys.     They  also  make 


General  Problems  233 

characteristic  confusions  of  greens  with  reds,  etc.  I  as- 
sume that  they  see  colours,  not  as  I  do,  but  quite 
dilferently;  and  that  they  fall  into  two  groups  (p.  151). 
Finer  experiments  and  measurements  cause  me  to  dis- 
tinguish still  other  persons  who  see  colours  differently. 
Still  finer  measurements  show  that,  whereas  the  ma- 
jority of  people  agree  with  my  results,  yet  each  one  of 
them  has  small  peculiarities.  In  this  way  I  proceed 
through  all  the  experiments  of  psychology  and  draw 
conclusions  concerning  the  resemblance  of  each  per- 
son's sensations,  feelings,  and  volitions  to  my  own. 

This  material  may  be  termed  the  "objective" 
as  contrasted  to  the  " introspective,"  or  "subjective," 
material. 

I  never  see  another  person's  feeling  of  pleasure  or 
his  sensation  of  colour.  Indeed,  I  can  never  hope  to 
do  so ;  for  all  anatomical  dissections  of  and  operations 
on  persons  reveal  only  inorganic  materials  such  as 
water,  salt,  etc.,  and  organic  forms  composed  of  cells. 
Yet  I  find  so  many  resemblances  between  the  responses 
of  a  living  person  to  those  I  make  myself  that  I  feel 
justified  in  assuming  that  he  has  a  mind  as  like  my 
own  as  the  experiments  point  out.  This  same  reason- 
ing applies  not  only  to  human  beings  but  to  animals. 
There  can  be  no  doubt  that  the  dog  who  performs 
reactions  (p.  46)  in  certain  experiments  just  as  I  would, 
has  the  mental  experiences  that  I  know  as  perception, 
discrimination,  choice,  and  volition.  We  can  thus 
build  up  the  mental  life  of  a  dog  with  its  colours, 
sounds,  volitions,  love,  anger,  fatigue,  etc.,  as  nearly'- 
like  our  own  as  the  experiments  justify  us  in  assuming. 

The  attempt  has  been  made  to  specify  some  special 


234       Thinking,  Feeling,  Doing 

part  of  the  body  as  the  place  where  the  person's  (or 
animars)  mental  life  is  located.  In  past  centuries 
speculation  has  asserted  the  liver,  or  the  heart,  etc.,  to 
be  such  an  "organ  of  mind."  At  the  present  day  we 
have  evidence  that  the  brain  is  the  organ  most  in- 
timately connected  with  our  mental  life.  This  evi- 
dence consists  mainly  of  cases  of  brain  disease,  where 
injifry  to  the  brain  is  found  to  have  accompanied 
mental  disturbance.  We  know,  for  example,  that 
softening  of  one  part  of  the  brain  is  accompanied  by 
"  mental  blindness,"  whereby  the  person  can  see  every- 
thing perfectly  but  can  not  recognise  it ;  he  sees  the 
candle  flame  but  may  call  it  a  hat  or  may  try  to  eat  it 
if  told  that  it  is  an  apple.  Such  localisations  of  the 
mental  faculties  are  very  valuable  in  medical  work 
but  the  study  of  them  is  hardly  in  place  in  an 
elementary  work  on  psychology. 

From  the  beginning  psychologists  have  attempted 
to  classify  the  contents  of  mind.  Such  items  as 
colours,  sounds,  tastes,  smells,  touches,  hot  and  cold 
impressions,  joint-,  muscle-  and  tendon-experiences, 
and  the  pains  have  been  lumped  together  as  "  sensa- 
tions "  ;  it  is  quite  convenient  to  keep  the  term  in  this 
sense  to  denote  merely  experiences  of  a  certain  kind. 
Experiences  of  another  kind  (p.  178)  we  term  the 
"feelings"  ;  those  of  still  another  kind  we  term  "  voli- 
tions "  or  acts  of  will.  Combinations  of  the  sensations 
produce  "  perceptions " ;  we  perceive  the  orange  as 
having  colour,  taste,  smell,  resistance,  form,  etc. 
Combinations  of  perceptions  with  the  traces  of  past 
experience  we  call  "apperceptions." 

All   these  experiences  we  regard  as  being  in  the 


General  Problems  235 

present ;  from  them  we  distinguish  others,  called 
"memories,"  which  carry  with  them  the  indications 
that  they  were  sensations,  feelings,  and  volitions  at 
some  past  time.  We  also  distinguish  the  "  imagina- 
tions "  from  the  rest  by  the  fact  that  we  regard  them 
as  unreal.  ''Hallucinations"  are  experiences  that  ap- 
pear, to  be  real  but  that  can  be  proven  to  be  unreal. 
By  "  ideas  "  we  generally  mean  summarised  abstracts 
of  our  memories  concerning  things  or  events  ;  some- 
times the  term  is  applied  to  groups  of  perceptions. 

"Sensations"  have  sometimes  been  defined  as  the 
elements  of  mental  life.  In  such  a  sense  there  are 
only  three  sensations  of  colour,  namely,  elementary 
red,  green,  and  blue ;  all  the  hues,  shades,  tints,  and 
greys  are  compounds.  The  six  feelings  and  the  vari- 
ous impulses  would  also  be  sensations  according  to 
this  classification.  Sensations  have  also  been  defined 
as  the  mental  experiences  due  to  external  stimulation. 
Thus,  colours  are  due  to  light  falling  upon  the  eye, 
tones  to  air-vibrations  coming  to  the  ear,  etc..  In  like 
manner  we  would  speak  of  the  sensations  from  the  lin- 
ing of  the  abdominal  cavity — the  peritoneum — which 
become  painful  in  colic,  or  sensations  from  the  duct  of 
the  gall-bladder  which  arise  during  the  passage  of  gall- 
stones, and  so  on,  although  the  external  stimulation  is 
within  the  body. 

Our  mental  life  is  governed  partl}^  by  the  impres- 
sions from  the  world  about  us.  A  certain  sound 
makes  us  think  of  the  door  bell ;  this  starts  us  to  go 
to  the  door.  A  diJfferent  sound  arouses  the  thought  of 
dinner  and  we  go  to  the  dining-room.  Still  another 
sound  sets  us  thinking  of  the  opera ;  scene  after  scene, 


236        Thinking,  Feeling,  Doing 

aria  after  aria  "passes  through  our  mind."  Such  ex- 
periences we  describe  by  saying  that  an  external 
stimulus  arouses  us  to  a  response  or  starts  associations 
of  ideas. 

The  response  to  a  stimulus  may  be  "  impulsive " 
like  the  jump  when  a  fire-cracker  goes  off.  It  is 
"  deliberate  "  when  we  take  our  time  about  it.  The 
reaction  in  the  first  case  is  a  simple  one  including  per- 
ception and  volition  (p.  30),  in  the  other  a  complex 
one  including  discrimination  and  choice  (p.  40). 

For  most  purposes  we  may  assume  that  the  associa- 
tion of  ideas  (p.  41)  proceeds  according  to  tlie  rule  of 
coincidence ;  an  idea  is  followed  by  one  that  has  some- 
thing in  common  with  it.  This  common  factor  may 
be  some  component;  e.  g.^  the  word  "street"  may  be 
followed  by  the  thought  of  the  word  "strong,"  both 
besinninor  with  the  same  letters  "str."  Or  the  com" 
mon  factor  may  be  the  larger  idea  of  which  both  ideas 
are  part ;e.^.  "  street"  may  be  followed  by  "car,'' 
because  both  have  occurred  as  parts  of  the  idea 
"street  car." 

This  rule  does  not  explain  why  on  one  occasion 
"  strong  "  is  associated  and  on  another  occasion  "  car." 
My  explanation  of  the  association  of  ideas  is  as  follows: 

Every  idea  in  the  mind  fades  away  at  first  rapidly, 
then  more  and  more  slowly  (see  the  memory  curve 
p.  209) ;  although  it  soon  becomes  so  faint  that  we  no 
longer  notice  it,  it  never  entirely  disappears ;  its  inten- 
sity approaches  zero  asymptotically,  as  the  mathema- 
ticians say.  "Whenever  the  same  idea  enters  the  mind 
again,  it  is  strengthened  by  what  remains  of  tlie  first 
one.     This  may  occur  any  number  of  times,  the  idea 


General  Problems  237 

gaining  each  time.  It  is  a  familiar  experience  with 
all  of  us  that  the  oftener  we  see  a  thing  the  more  often 
it  comes  into  the  mind  at  other  times. 

This  law  holds  good  of  each  element  of  the  ideas ; 
like  elements  fuse  although  they  may  be  in  different 
ideas.  For  example,  the  elements  "  s-t-r  "  fuse  together 
when  such  a  series  of  words  as  "  struggle,  strive,  strict, 
straw,  strong,"  etc,  is  repeated.  Now  let  a  new  idea 
enter,  say  "  street " ;  the  elements  "  str "  fuse  with 
the  same  ones  of  the  series  of  words  and  this  makes 
them  so  strong  that  they  determine  the  association. 
This  is  why  "strong"  is  associated  and  not  "car." 
We  can  carry  the  same  principle  further  and  explain 
why  "  strong  "  and  not  "  strive  "  was  associated.  These 
principles  the  reader  can  investigate  for  himself.  He 
can  have  a  person  read  over  many  times  a  long  list 
of  words;  then  on  calling  out  to  him  some  word,  he 
will  be  able  to  notice  the  influence  of  the  list  on  the 
associations. 

There  are  thus  three  fundamental  laws  of  association 
of  ideas :  1,  each  element  of  an  idea  persists  in  an  in- 
tensity that  steadily  decreases  toward  but  never  reaches 
zero ;  2,  es^ery  element  of  an  idea  adds  its  intensity  to 
the  residual  intensity  of  every  preceding  element  of 
the  same  kind ;  3,  an  element  adds  to  the  intensity 
of  any  other  element  with  which  it  was  previously 
connected. 

During  our  waking  hours  our  associations  of  ideas 
are  continually  started  anew  by  impressions  from  the 
world  about  us ;  the  persons  talking  to  us,  the  sights 
we  see,  the  sounds  we  hear,  all  force  us  to  think 
along  certain  lines.    In  revery  we  are  left  more  to  our- 


238        Thinking,  Feeling,  Doing 

selves  and  our  tlioaglits  have  freer  play.  In  sleep  the 
impressions  from  outside  are  few  and  weak  ;  we  dream 
long  continued  stories  which,  freed  from  outside  in- 
f]uences,  may  appear  quite  absurd  when  we  awake. 
Yet,  although  our  thoughts  are  freest  in  dreams,  they 
are  still  influenced  by  impressions  from  the  skin, 
intestines,  etc. 

"Is  mind  governed  by  law?  "  By  "law"  we  mean 
an  established  sequence  of  events.  If  we  let  go  of 
a  box,  it  falls  to  the  ground ;  this  we  say  is  an  illustra- 
tion of  the  law  of  gravitation.  If  the  box  does  not 
fall,  we  may  do  one  of  two  things.  We  may  say: 
"  Here  is  a  case  that  does  not  conform  to  law ;  there- 
fore we  must  admit  the  existence  of  mysterious  forces 
concerning  which  we  are  at  liberty  to  believe  anything 
we  please."  Such  reasoning  produces  the  "mystics," 
whose  fundamental  principle  is,  that,  since  there  are 
things  we  cannot  explain  by  laws,  therefore  belief  is 
at  liberty  to  set  up  any  laws  it  pleases.  This  is  the 
basisof  clairvoyance,  spiritualism,  thought-transference, 
telepathy,  palmistry,  and  similar  delusions. 

When  the  box  does  not  fall,  the  common-sense  man 
says:  "The  case  apparently  does  not  conform  to  law, 
but  let  us  inquire  if  some  unseen  or  undiscovered 
force  is  not  counteracting  gravitation.  Even  if  I  my- 
self cannot  find  it,  yet  I  believe  only  in  the  action  of 
forces  according^  to  laws  and  I  will  search  for  the  hid- 
den  one  or  leave  more  able  men  to  do  so."  On  inves- 
tigating the  box  he  finds  an  unnoticed  string  that  holds 
it  up,  or  some  similar  arrangement  that  had  escaped 
him.  Men  of  this  kind — whether  trained  or  not — are 
men  of  scientific  habits  of  thought.     The  advance  of 


General  Problems  239 

science  is  one  continuous  battle  of  the  scientists  against 
the  mystics. 

Applying  the  principles  of  science  to  mental  life,  we 
establish  the  laws  of  reaction,  of  habit,  etc.  Where 
these  laws  do  not  suffice,  we  simply  say  so  and  wait 
for  further  information  ;  we  absolutely  reject  all  mystic 
explanations.  Mind,  therefore,  we  assume  to  be  gov- 
erned by  law  even  to  its  finest  details. 


CHAPTER   XXI 

MATERIALISM   AND   SPIRITUALISM   IN    PSYCHOLOGY 

IN  the  good  old  days,  now  happily  gone  forever, 
when  psychology  was  a  matter  of  doctrine,  we 
used  to  hear  of  materialistic  psychology,  spiritualistic 
psychology,  the  psychology  of  Hamilton,  the  psycho- 
logy of  Hegel,  English  psychology,  German  psychology, 
etc.,  etc. 

Nowadays  it  is  just  as  absurd  to  speak  of  anybody's 
system  of  psychology  as  to  speak  of  anybody's  system 
of  chemistry.  There  is  one  science  of  chemistry  to 
which  all  scientific  chemists  are  contributors  ;  there  is 
one  science  of  psychology  which  all  scientific  psycholo- 
gists make  their  humble  efforts  to  develop.  How  this 
has  come  about  I  am  going  to  tell  by  translating  a  few 
pages  from  Wundt's  Yorlesungen  uher  Menschen  und 
Thierseele. 

"  The  earliest  psychology  is  materialism.  The  soul 
is  air  or  fire  or  an  ether  ;  it  remains,  however,  material 
nothwithstanding  the  efforts  to  lighten  and  thereby  to 
spiritualise  the  matter.  Among  the  Greeks  it  was  Plato 
Avho  first  freed  the  soul  from  the  body,  whereby  he 
made  it  the  ruling  principle  of  the  latter.  He  thus 
opened  the  path  for  the  one-sided  dualism  which  re- 
garded sensory  existence  as  the  contamination  and 
degradation  of  a  purely  mental  being.     Aristotle,  who 

240 


Materialism  and  Spiritualism      241 

united  a  wonderful  sharpness  of  observation. to  his  gift 
of  speculation,  sought  to  soften  this  contrast  by  infusing 
the  soul  into  matter  as  the  vivifying  and  constructive 
principle.  In  the  animals,  in  the  expression  of  the 
human  form  in  repose  and  motion,  even  in  nourishment 
and  growth,  he  saw  direct  effects  of  mental  forces,  and 
he  drew  the  general  conclusion  that  the  soul  brings 
forth  all  organic  form  just  as  the  artist  forms  the  block 
of  marble.  Life  and  soul  were  for  him  the  same  ;  even 
the  plant  had  a  soul.  Yet,  Aristotle,  like  no  one  before 
him,  had  studied  into  the  depths  of  his  own  conscious- 
ness. In  his  work  on  the  soul,  the  first  book  treating 
psychology  as  an  independent  science,  we  find  the 
fundamental  processes  carefully  distinguished  and — 
as  far  as  possible  in  his  time — explained  as  to  their 
relations. 

"  The  Aristotelian  psychology,  and  especially  its 
fundamental  doctrine  that  the  soul  is  the  principle  of 
life,  governed  the  whole  of  the  Middle  Ages.  At  the 
beginning  of  modern  times  here,  as  in  other  subjects, 
a  return  to  the  Platonic  views  began  to  weaken  its 
power.  Soon  a  new  influence  was  associated  :  the  re- 
vival of  the  modern  natural  sciences  and  the  mechanical 
views  of  the  world  which  they  spread  abroad.  The 
result  of  the  conflict  was  the  birth  of  two  fundamental 
views  in  psychology,  which  down  to  the  present  day 
have  fought  each  other  in  the  field  of  science  :  spirit- 
ualism and  materialism.  Strange  to  say,  the  very  same 
man  was  of  primary  importance  for  the  development 
of  both.  Descartes,  no  less  great  as  mathematician 
than  as  philosopher,  defined,  in  opposition  to  the  Aris- 
totelian psychology,  the  soul  exclusively  as  a  thinking 
being  ;  and,  following  the  Platonic  views,  he  ascribed 

to    it  an   existence,   originally  apart   from  the  body, 
16 


242         Thinking,  Feeling,  Doing 

whence  it  derived  as  permanent  property  all  those  ideas 
which  go  beyond  sensory  experience.  Itself  occupying 
no  space,  this  soul  was  connected  with  the  body  at  one 
point  of  the  brain,  in  order  to  receive  the  influences 
from  the  outer  world  and  in  its  turn  to  exercise  its  in- 
fluence on  the  body." 

The  later  spiritualism  advanced  but  little  beyond 
this  theory  of  Descartes.  Its  last  great  representative 
was  Herbart.  He  developed  in  thoroughly  logical 
manner  the  idea  of  a  simple  soul  substance,  according 
to  Descartes.  Herbart  was  of  very  great  service  to  the 
new  psychology  in  a  certain  way,  and  we  shall  say 
something  about  his  work  later,  but  his  spiritualistic 
psychology  was  a  total  failure.  His  attempts  at  de- 
ducing the  facts  of  mental  life  from  the  idea  of  a  simple 
soul  and  its  relations  to  other  beings  proved  fruitless. 
His  efforts  showed  more  clearly  than  anything  else 
could  do  that  this  pathway  was  an  impossible  one 
for  psychology.  The  idea  of  a  simple  soul  substance 
had  not  been  derived  from  actual  observations  of 
mental  life,  but  had  been  arbitrarily  and  unreasonably 
asserted ;  the  facts  were  to  be  forced  to  fit. 

Descartes  contributed  to  the  development  of  modern 
materialism  in  two  ways,  by  his  strictly  mechanical 
view  of  nature  in  general  and  by  his  treatment  of  ani- 
mals as  automats.  Man  alone  had  a  mind ;  animals 
were  machines.  But  if  the  many  evidences  of  thinking, 
feeling,  and  willing  among  animals  can  be  explained 
physiologically,  why  cannot  the  same  explanation  be 
used  for  man  ?  This  was  the  starting  point  for  the 
materialism  of  the  seventeenth  century. 

*'  For  materialism  all  facts  of  thinking,  feeling,  and 


Materialism  and  Spiritualism      243 

doing  are  products  of  certain  organs  in  the  nervous  sys- 
tem. Any  observation  of  the  facts  of  mind  is  valueless 
until  such  facts  can  be  explained  by  chemical  and  physi- 
cal processes.  Thinking  is  a  production  of  the  brain. 
Since  this  process  stops  when  the  circulation  of  the 
blood  stops  and  life  ceases,  therefore  thought  is  nothing 
but  an  accompaniment  of  the  materials  of  which  the 
brain  is  composed." 

Down  to  the  present  day  modern  materialism  has  not 
gotten  beyond  this  point — mental  life  is  a  product 
of  the  brain  ;  psychology  is  merely  physiology  of  the 
brain. 

"  Our  feelings,  thoughts,  and  acts  of  will,  however, 
cannot  be  observed  as  all  phenomena  of  nature,  have 
been  observed.  We  can  hear  the  word  that  expresses 
a  thought,  we  can  see  the  man  who  formed  it,  we  can 
dissect  the  brain  that  thought  it;  but  the  word,  the 
man,  the  brain — these  were  not  the  thought." 

A  feeling  of  anger  is  accompanied  by  an  increase  of 
blood  in  the  brain  ;  but  no  matter  how  minute  our 
knowledge  of  the  chemical  processes  between  the  blood 
and  the  brain  substance  may  be,  we  know  that  we  can 
never  discover  the  chemistry  of  anger. 

But,  says  materialism,  these  material  processes  may 
not  be  the  thoughts,  yet  they  produce  them.  Just  as 
the  liver  produces  bile,  just  as  the  contraction  of  mus- 
cle causes  motion,  so  are  our  ideas  and  emotions  pro- 
duced by  blood  and  bram,  by  heat  and  electricity.  Yet 
a  very  important  difference  has  been  overlooked.  We 
can  show  how  the  bile  is  produced  by  chemical  process 
in  the  liver  ;  we  can  show  how  the  movement   is  the 


244        Thinking,  Feeling,  Doing 

result  of  chemical  processes  in  the  muscle ;  but  brain 
processes  give  us  no  information  of  the  way  thoughts 
are  produced.  We  can  understand  how  one  bodily 
movement  produces  another  movement,  how  one  emo- 
tion or  sensation  chansres  to  another  motion  or  sensa- 
tion ;  but  how  a  motion  of  molecules  or  a  chemical 
process  can  produce  thought  is  what  no  system  of 
mechanics  can  make  clear. 

These  vagaries  of  materialism  have  called  attention 
to  the  study  of  the  relations  between  mind  and  brain, 
and  we  have  had  "mental  physiologies,"  even  from 
those  who  are  not  materialists.  The  study  of  what 
happens  in  the  brain  or  in  any  part  of  the  body  when 
we  are  angry,  or  when  we  think  of  an  apple,  is  of  course 
an  immensely  valuable  thing.  The  absurdity  arises 
when  it  is  asserted  that  every  mental  fact  is  merely  an 
appendix  to  some  brain  process  ;  that,  for  example,  we 
do  not  feel  merry  at  the  thought  of  a  joke,  but  that  cer- 
tain chemical  processes  in  the  brain  produced  the 
thought  of  the  joke  and  at  the  same  time  set  going  other 
chemical  processes  that  produced  the  merry  feeling. 
There  are  many  volumes  of  so-called  "  psychology  "  in 
which  each  mental  process  is  translated  into  some  im- 
aginary (for  we  have  no  facts  on  the  subject)  move- 
ment of  brain  molecules,  which  in  some  imaginary 
fashion  sets  up  another  imaginary  movement,  which  is 
translated  into  a  second  mental  process  that  really  fol- 
lowed the  first  one  according  to  a  simple  psychological 
law. 

But  the  strife  between  spiritualism  and  materialism 
is  almost  passed. 


Materialism  and  Spiritualism      245 

"It  has  left  uo  contribution  to  science,  and  no  one 
who  carefully  examines  the  subject  of  the  strife  can 
wonder  at  such  a  result.  For  what  was  the  central  point 
of  the  battle  of  opinions?  About  nothing  else  than 
the  questions  concerning  the  soul,  its  seat,  its  connec- 
tion with  the  body.  Materialism  here  fell  into  the  same 
fault  as  spiritualism.  Instead  of  beginning  upon  the 
facts  that  were  observed  and  investigating  their  rela- 
tions, it  busied  itself  with  metaphysical  questions  for 
which  answers  can  be  found  only — if  ever — through  a 
completely  unprejudiced—/,  e.,  at  the  start  free  from 
every  metaphysica.  supposition — investigation  of  the 
facts  of  experience." 

Starting  from  entirely  different  points  of  view,  both 
spiritualism  and  materialism  have  landed  in  utterly 
fruitless  suppositions.  The  reason  lay  in  the 
methods  which  they  employed.  To  suppose  that  any- 
thing could  be  gained  by  vague  speculation  on  mental 
life  was  folly  equalled  only  by  the  belief  that  dissect- 
ing brains  would  lead  to  a  knowledge  of  mind.  Both 
parties  forgot  one  point— namely,  to  examine  the  facts 
of  mind  itself. 

It  is  this  forgotten  duty  that  led  to  the  new  psy- 
chology— a  psychology  of  fact.  This  psychology  of 
mental  life,  this  science  of  direct  investigation  of  our 
thinking,  feeling,  and  doing,  is  neither  spiritualism  noi- 
materialism  ;  it  has  no  speculations  of  either  kind  to 
offer.  It  confines  itself  strictly  to  the  domain  of  fact. 
As  long  as  they  can  set  themselves  in  harmony  with 
the  facts,   the  Hegelian  philosopher  and  the  Feuer- 


246         Thinking,  Feeling,  Doing 

bachian  materialist  have  equal  rights.  When  they  go 
beyond  the  facts,  they  may  settle  the  question  between 
them ;  the  new  psychology  is  very  thankful  that  it 
has  nothing  to  do  with  either. 


CHAPTER  XXII 

THE   NEW    PSYCHOLOGY 

THE  facts  we  have  been  considering  in  this  book 
have  been  facts  of  mind,  not  of  the  physical 
world.  The  beautiful  colours  we  see  are — the  physi- 
cists tell  us — only  vibrations  of  ether;  the  physical 
world  has  no  colour,  the  colours  exist  only  when  we 
are  present.  Physical  vibrations  of  the  air  are  to  us 
tones.  Certain  mechanical  movements  are  to  us 
pressures.  Feelings  and  will-impulses  may  betray 
themselves  by  movements  or  otherwise ;  in  themselves 
they  are  mental  facts.  In  short,  we  may  say  that  all 
the  facts,  as  we  know  them,  are  mental  facts.  The 
science  of  these  facts  is  psychology. 

But  what  is  the  new  psychology  ?  The  new  psy- 
chology is  entitled  to  its  special  adjective  because  it 
employs  a  method  new  in  the  history  of  psychology, 
although  not  new  in  the  history  of  science. 

The  old  ps3^chologist,  like  Locke,  Hamilton,  and 
miiny  of  the  present  day,  sits  at  his  desk  and  writes 
volumes  of  vague  observation,  endless  speculation, 
and  flimsy  guesswork.  The  psychologist  of  the  new 
dispensation  must  see  every  statement  proven  by 
experiment  and  measurement  before  he  will  commit 
himself  in  regard  to  it. 

The  difference  between  the  old  and  the  new  is  not 

247 


248         Thinking,  Feeling,  Doing 

one  of  material ;  the  subject  is  the  same  for  both, 
namely,  the  facts  of  mind.  The  difference  lies  in  the 
carefulness  with  which  the  information  in  regard  to 
these  phenomena  is  obtained.  Instead  of  careless 
observation  and  guesswork  the  utmost  care  and  self- 
sacrificing  labour  are  expended  in  the  laboratory  in 
order  to  obtain  single  facts.  This  method  of  careful, 
scientific  work  is  unintelligible  to  the  men  of  the  old 
school.  The  method  of  experiment  "  taxes  patience 
to  the  utmost"  and  "could  hardly  have  arisen  in  a 
country  whose  natives  could  be  horedr 

Who  are  the  men  to  whom  we  owe  the  regeneration  ? 
Of  course,  the  psychological  awakening  is  only  a  part 
of  the  great  movement  by  which  many  of  the  sciences 
have  successively  emerged  from  the  scholasticism  of 
the  Middle  Ages.  Mathematics,  physics,  chemistry, 
biology,  and  others  are  now  free  and  fruitful  sciences ; 
psychology  has  just  joined  the  group. 

Sir  William  Hamilton  is  the  one  to  whom  we  must 
look  back  as  having  vindicated  the  right  to  build 
psychology  upon  observations  and  not  to  deduce  it 
from  philosophical  prejudices. 

In  Germany  the  natui'al  revolt  from  the  dull  scho- 
lasticism of  the  psychology  of  Wolff  and  the  mad 
speculation  of  Schelling  was  led  by  Herbart.  The 
philosopher,  psychologist,  and  educator,  Herbart, 
was  born  in  1776.  He  became  professor  of  philos- 
ophy at  Gottingen ;  later  he  succeeded  Kant  as  pro- 
fessor of  philosophy  in  Konigsberg,  where  he  died 
in  1841.  He  is  best  known  for  his  works  on  education; 
these,  being  founded  on  his  psychology,  have  led  edu- 
cational people  to  adopt  the  Herbartian  psychology 


The  New  Psychology 


249 


with  the  Herbartian  pedagogy.  The  Herbartian 
pedagogy,  with  the  improvements  of  its  followers 
is,  to-day  perhaps  the  best  s^'stem  and  guide  that 
we  have. 

To  Herbart  as  a  psychologist  we  also  owe  a  debt. 
The  old  faculty- 
psychology,  with  its 
groundless  and  end- 
1  e  s  s  speculation, 
aroused  his  ire  ;  he 
set  about  producing 
a  new  psychology. 
In  the  first  place, 
he  determined  to 
start  from  the  facts 
as  he  observed  them 
in  his  own  mind ; 
this  was  in  itself  a 
great  step.  You 
have  probably 
heard  of  the  medise- 

Val  student,   who  at  Fig.  1S4.— Johann  Friedrich  Herbart. 

the  time  when  the  discovery  of  spots  on  the  sun  began 
to  be  talked  about,  called  the  attention  of  his  old  in- 
structor to  them.  The  reply  was:  "There  can  be  no 
spots  on  the  sun,  for  I  have  read  Aristotle's  works 
from  beginning  to  end  and  he  says  the  sun  is  incor- 
ruptible. Clean  your  lenses,  and  if  the  spots  are  not 
in  the  telescope,  they  must  be  in  your  eye." 

This  debt  we  owe  to  Herbart  is  a  great  one;  the 
other  debt  we  owe  him  is  for  a  different  reason.  Math  - 
ematics,  we  all  know,  is  the  fostering  mother  of  the 


250         Thinking,  Feeling,  Doing 

sciences.  What  was  more  natural  than  to  place  a 
discredited  psychology  in  her  care?  This  is  what 
Ilerbart  attempted.  On  the  basis  of  his  observations 
he  proceeded  to  build  up  his  mathematics  of  ideas. 
His  results  are  very  curious ;  for  example,  if  you  have 
an  idea  in  your  mind  and  another  one  wishes  to  get 
in,  there  occurs  a  strife  between  them  and  they  press 

against  each  other  with  a  force  proportional  to       — — . 

Of  course,  the  whole  thing  was  ahead  of  time.  Mathe- 
matics makes  use  of  symbols  for  quantities  ;  when  you 
speak  of  a  distance  ^,  you  mean  just  so  many  inches  or 
centimeters  or  miles  ;  t  represents  a  number.  But  when 
Herbart  speaks  of  an  idea  with  the  intensity  a,  there 
is  no  method  of  giving  any  quantitative  indication  of 
how  great  this  intensity  is ;  he  knows  of  no  measure  of 
intensity,  and  his  use  of  symbols  is  absolutely  mean- 
ingless. No  mathematician  would  ever  dream  of  such 
folly.  Herbart  revolted  against  metaphysical  specula- 
tion, but  fell  into  a  kind  of  mathematical  speculation 
that  was  no  less  futile. 

But  if  all  that  was  lacking  was  merely  the  quantita- 
tive expression  for  psychological  facts,  why  not  get  to 
work  and  measure  them,  just  as  in  astronomy  and 
physics  ?  But  how  ?  How  can  we  measure  the  in- 
tensity of  a  pain,  or  the  time  of  thought,  or  the  extent 
of  touch  ?  The  matter  seemed  to  Herbart  really  incom- 
prehensible. 

One  of  the  surest  ways  of  being  put  in  the  wrong  is 
to  say  that  something  can  never  be  done.  Comte,  the 
philosopher,  once  said  that  it  would  be  forever  impos- 
sible to  tell  the  composition  of  the  stars ;  forty -three 


The  New  Psychology  251 


years  later  the  use  of  the  spectroscope  enabled  astrono- 
mers to  analyse  each  one.  Herbart  declared  that 
"  psychology  must  not  experiment  with  man  ;  and 
instruments  thereto  do  not  exist";  in  another  place  he 
asserts  that  "  psychological  quantities  are  not  presented 
in  such  a  way  that  they  can  be  measured ;  they  allow 
only  an  incomplete  estimate."  Nineteen  years  later 
Fechner  published  his  great  work  on  psychophysics,  in 
which  he  showed  how  to  experiment  on  mental  pro- 
cesses and  measure  psychological  facts. 

Other  influences  had  been  tending  toward  the  de- 
velopment of  psy- 
chology, and,  al- 
though Fechner 
was  the  first  really 
to  start  the  new 
psychology,  he  is 
only  the  logical 
outcome  of  the  pro- 
gress of  thought  in 
other  lines. 

Both  the  physi- 
cist and  the  physi- 
ologist frequently 
come  to  problems 
where  mental  life 
is  involved.  Phy- 
sicists still  amuse 
themselves  by  the 

so-called  optical  illusions  and  the  beautiful  pheno- 
mena of  contrast,  although  there  is  not  a  particle  of 
physics  in  any  way  connected  with  the  subject.     Phy- 


FiG.  Ibo  .— Gustav  Theodor  Fechner. 


252        Thinking,  Feeling,  Doing 


siologists  have  always  been  forced  to  consider  questions 
of  sensation,  emotion,  and  volition,  in  order  to  draw  con- 
clusions in  regard  to  bodily  processes.  Many  names 
might  be  mentioned  in  this  connection,  but  one 
is  of  special  importance,  that  of  Ernst  Ileinrich 
Weber.  This  distinguished  physiologist  and  phy- 
sicist wrote  a  semi-psychological  treatise  on  "  Sen- 
sations of  Touch  and  the  Internal  Feelings,"  which 
not  only  induced  later  physiologists  to  continue  the 
work,  but  was  also  the  direct  stimulus  for  Fechner. 
This  influence  we  may  call  the  physiological  one ;  it  has 

done  its  main  psy- 
cholo2:ical  service 
in  outlining  the 
sensations  in  a 
qualitative  manner. 
Fechner  may  be 
considered  as  the 
builder  of  psycho- 
logy representing 
the  final  passage 
from  the  qualitative 
to  the  quantitative. 
Fechner  (1801- 
1887)  was  the  foun- 
der of  experimen- 
tal p  s  y  c  h  o  1  o  g  y. 
While  professor  of 
physics  at  the 
University  of  Leipzig  he  invented  and  worked  out  the 
methods  which  we  have  used  in  finding  the  threshold 
(see    Index).       His    greatest    works    were,    Elemente 


■ 

n 

■ 

^B 

f*                         ^am 

M*" 

^\ 

'Sh^                      1^ 

^^^Hb  ^ 

n 

^f""" 

"'1 

tW^^^^ 

vy 

ki^i 

Fig.  ISO. — Hermann  von  Helmholtz. 


The  New  Psychology  253 

der  Psychophysik  and  Revision  der  Hauptunkte  der 
Psychophysik.  So  much  of  Fechner  is  embodied 
in  all  our  psychological  work  that  it  is  useless  to  at- 
tempt more  than  to  indicate  his  main  services.  I 
will  sum  them  up  as :  (1)  the  invention  of  new  methods 
of  measuring  the  intensity  of  sensations ;  (2)  the  in- 
troduction of  new  methods  of  calculating  results  ;  (3) 
the  development  of  laws  concerning  the  relation  of  in- 
tensities of  sensations ;  (4)  the  foundation  of  experi- 
mental aesthetics ;  and  (5)  numerous  smaller  investi- 
gations and  observations. 

A  greater  than  Fechner  was  to  come.  Mathematician, 
physicist,  physiologist,  psychologist,  and  technologist, 
Hermann  von  Helmholtz  has  given  to  the  psychology 
of  sight  and  hearing  the  best. his  sciences  had  to  give. 
We  cannot  claim  him  as  a  psychologist,  his  genius 
was  too  great  for  a  science  still  so  limited.  Neverthe- 
less there  are  few  to  whom  psychology  owes  more. 

We  must  turn  back  to  the  last  century  for  a  second 
current  of  thought  that  was  to  develop  psychology. 
This  time  it  was  an  astronomer  puzzled  by  mistakes  of 
his  own  method  The  story  has  been  told  in  chapters 
III  and  XIX.  The  time  measurements  of  mental 
phenomena  were  afterwards  taken  up  and  developed 
by  Wundt,  in  whose  laboratory  they  are  still  conti- 
nually pushed  further. 

Wilhelm  Wundt,  born  at  ISTeckerau  in  Baden  in 
1832,  was  a  student  of  medicine  at  Tubingen,  Heidel- 
berg, and  Berlin.  His  academical  career  began  with  a 
place  as  instructor  in  physiology  at  Heidelberg,  where 
in  1863  he  published  his  Lectures  on  Human  and  Animal 
Psychology.        In     1864     he  was      made      assistant 


254       Thinking,  Feeling,  Doing 


professor  of  physiology.      In  1866  he  published  The 
Physical  Axioms  and  their  Relations  to  the  Principles  of 

Causality.  In  1874 
he  published  the 
Outlines  of  Phys- 
iological Psychology. 
In  the  same  year 
he  was  called  to 
Zurich  as  professor 
of  philosophy,  in 
1875  to  Leipzig, 
riis  later  works 
have  covered  most 
-cctions  of  phil- 
( )Sophy  :  Logic^  Es- 
says, Ethics^  System 
of  Ph  ilosophy.  H  i  s 
latest  achievement 
is  his  Folk  Psy- 
chology. The  insti- 
tute at  Leipzig  lias  taken  up  not  only  the  time 
measurements  and  the  work  begun  by  Fechner,  but 
also  nearly  every  portion  of  psychology  accessible  to 
experiment. 

These  men  are  merely  the  most  prominent  figures  in 
the  army  of  investigators  that  has  created  the  new 
psychology.  The  others  are  no  less  deserving  of 
credit  but  it  is  impossible  to  mention  them  singly  on 
account  of  their  multitude. 


Fig.  187.— Wilhelm  Wundt. 


INDEX 


Accidents  due  to  colour- 
blindness,  136 

Accuracy  of  singing,  67;  of 
tone-judgment,  112 

Action,  13 

Activity,  191 

Acts  of  will,  15 

Acuteness  of  smell,  96 

Addition,  time  of,  42 

Advertising,  196,  211 

-^sthesiometer,  83 

i^sthetics,  see  Feeling 

After-images,  143 

Age,  effect  on  highest  audible 
tone,  104;  see  also  Children 

Agreeable,  see  Like 

Air-transmission,  61 

Alcoholism,  33 

Alliteration,  212 

Alphabet,  see  Letters 

Alternation  of  odours,  95 

American  flag,  136 

Anger,  190,  191 

Angle  illusion,  154 

Animal  psychology,  5,  242 

Anirnals,  reaction-time  of,  47; 
highest  audible  tones  of, 
105 

Ants,  5 

Apathy,  191,  192 

Apperception,  234 

Arhythmic  action,  59 

Aristotle,  240 

Aristotle's  illusion,  85 

Arithmomania,   202 

Arm,  time  of  movement,  45; 
steadiness  of,  62 

Arm-chair    psychology,     229 

Association  of  ideas,  41,  236 

Association-time,  41 


Astronomers,  27,  225 
Atmosphere,  161 
Attention,  effect  on  time  of 
movement,  21;  distraction 
of,    23,   32;    effect  on    res- 
piration, heart    and  blood 
vessels,      186;     systematic 
treatment    of,    193;     focus 
and  field  of ,  194;  instability 
of,  195;  extent  of,    195;  in 
children,  196;  forcing,  196; 
law  of    bigness,    196;    law 
of     brightness,     197;     law 
of  feeling,  198;  law  of  ex- 
pectation,     199;     law     of 
change,    200;    diseases   of, 
202;    effect  on    astronom- 
ical records,  225 
Audiometer,  115 
Automatic  reactions,  40 
Average  change,  204 
Average  uncertainty,  205 
Average  variation,  29 

Backhand  writing,  24 
Baton,  56 

Beauty  and  bigness,  198 
Binaural  audition,     118 
Binocular  contrast,  176 
Binocular  lustre,   175 
Binocular  relief,  169 
Binocular  vision,  163 
Black,  124 
Blackness,  124 
Blind-spot,  148 
Blind-spot  diagrams,   149 
Blind-spot    space    not    con- 
tracted, 150 
Blocks  for  suggestion,  219 
Blood  vessels,  method  of  re- 


255 


256 


Index 


Blood  vessels — (continued) 
cording   changes,    186;    re- 
sponse   to   emotions,    186- 
190 

Blue  and  yellow,  128 

Boiling  a  frog,  90 

Book-stereoscope,  166 

Boxer,  45 

Boys,  see  Children 

Breathing,  method  of  record- 
ing, 185;  afifected  by  emo- 
tions, 186-190 

Brightest  colours,  121 

Broken  tents  and  shades,  122 

Capsules,  50,  61,  67 

Chagrin.  191 

Chain-reaction,  26,  40 

Change,  least  noticeable,  79, 
90,  111;  effect  on  attention, 
200 

Children,  experiments  in 
tapping,  18;  indication  of 
fatigue,  22;  reaction-time, 
36;  thinking-time,  47; 
weight  judgments,  71;  dis- 
crimination in  pitch,  111; 
field  of  vision,  147;  mem- 
ory, 215;  suggestion,  22, 

Choice-time,  39 

Clinical  observation,  230 

Coincidence,  in  association 
of  ideas,  236 

Coin  illusion,  156 

Cold,  reaction  to,  35;  sensa- 
tions of,  87 

Cold  colours,  132 

Cold  spots,  88 

Colour,  effect  on  power  of 
action,  76;  sensations  of, 
120;  system  of,  122;  effect 
on  feelings,  179 

Colour-blindness,   130 

Colour-disk,  123 

Colour-equation,  131 

Colour-perimetry,  146 

Colour-sense  tester,  178 

Colour-sensitiveness,    130 

Colour- top,  123 

Colour-triangle,  127 


Colour-weakness,  139,   140 
Colour-wheel,  123 
Combination  of  colours,  123, 

125,  180 
Combination  of  paints,  126 
Compass,  83 
Complementary  colours,  125. 

180 
Comte,    250 
Contrast,  142,  180 
Cornice  illusion,  158 
Cross-education,    22,    66,   72, 

85 
Cross-memory,  206 
Crossed  disparity,  168 
Crushing  a  frog,  81 
Curve  of  habit,  31 
Curve  of  practice,  31 

Dal  ton,  141 

Delicacy  of  touch,  hearing, 
etc. ,  see  Threshold 

Depression,  189,  191,  192 

Depth  of  objects,  159 

Descartes,  242 

Despair,  191 

Dichromats,   131 

Difference,  see  Least  notice- 
able difference 

Disagreeable,  see  Dislike 

Discrimination  and  choice, 
40 

Discrimination-time,    39,    47 

Disease,  reaction-time  in, 
33 

Dislike,  188,  190 

Dislike,  for  colours,  123,  128; 
for  contrast,  142 

Disparity,  168 

Displeasure,   191 

Distance  of  objects,  159 

Distance  of  unknown  objects, 
199 

Distraction,  influence  on 
tapping,  163;  on  reaction- 
time,  32 

Dog,  reaction-time  of,  46 

Dreaming,  238 

Drum,  recording,  13,  29, 
52,  53,  62 


Index 


257 


Duration,  of  tones,   101 ;  no- 
tation for,  116 
Dynamograph,  74 
Dynamometer,  69 

Ecstasy,  202 

Education,  in  observing,  8; 
in  rapid  perception,  9;  in 
reaction  and  association, 
494  in  steadiness,  64;  of 
power,  72;  of  touch,  85;  of 
smell,  98;  01  memory,  210: 
see  also  Cross-education. 

Electric  baton,    57 

Electric  shoe,  53, 

Emotion,  191;  as  a  source  of 
illusion,  162 

Energy,  reserve  of,  23 

Enlarged  angle,  153 

Equation,  personal,  27,  225; 
of  colour,  131 

Error,  in  observation,  2;  of 
prejudice,  2;  of  uncon- 
scious additions,  4 ;  in  ani- 
mal psychology,  5;  of 
untrustworthiness  of  the 
senses,  7;  of  reproduction, 
70;  in  memory,  see  Mem- 
ory 

Exaltation,  191 

Excitability,  191 

Excitement,  16 

Expectation  and  attention, 
199;  and  suggestion,  217; 
effect  on  astronomical  re- 
cords, 225 

Experiment,  nature  of,  1 1 ; 
kinds  of,  11;  reliance  on, 
230;  introduced  into  psy- 
chology, 251 

Extent  of  attention,  195 

Eye  and  ear  method,  226 

Faraday,  2 

Fastest  tapping,  telegraph- 
ing, etc.,  see  Tapping,  Tele- 
graphing, etc. 

Fatigue,  16,  22,  64,  94,  143 

Fatigue-index,  22,  23 

Fear,  191 

11 


Fechner,  251,  252 

Feeling,  177 

Feelings,  and  taste,  177;  and 
colour,  179;  and  form,  182; 
stimulating,  185;  depress- 
ing, 185;  and  tension,  185; 
and  relaxation,  185;  and 
attention,  198;  relation  to 
other  mental  states,  234 

Fencing,  42 

Field   of   attention,    194 

Field  of  vision,  145 

Filled  space,  154 

Fixed  ideas,  202 

Flag,  American,  as  it  appears 
to  colour-blind  persons, 
136 

Flag-foil,  43 

Flash-light  pictures,  36 

Fluctuating  rings,    158 

Fluctuating  stair,  158 

Focus  of  attention,   194 

Force  of  act,  72 

Force  of  will,  72 

Forced  association,  42 

Fork,  electric,  13,  29,  115; 
with  mirror,  67;  for  tick- 
ling, 78;  giant  fork  for 
lowest  tones,  102;  of  ad- 
justable pitch,  107 ;  for  least 
noticeable  differences,   108 

Fork-record,  14 

Free  association,  42 

Frog,  experiments  on,  81,  90 

Fundamental  colours,  126 

Fundamental  fact  of  binocu- 
lar relief,  169 

Fundamental  method  of  ac- 
quiring knowledge,  1 

Gain  by  habit,  32 

Gain  by  practice,  31 

Galilei,  230 

Galton  whistle,  103 

Game  of  twenty  questions,  4 

Gas-capsule,  67 

Gauge  for  steadiness,  64 

German  type,  38 

Girls,  see  Children 

Going  up-stairs,  52 


258 


Index 


Graphic  method,  13,  24,  33, 
42,  45,  52,  53,  56,  59,  61, 
75,  185 

Grasp  of  attention,  195 

Grating,  125 

Green-blindness,  132,  134 

Greys,  120 

Guido  Aretino,  116 

Gun,  steadiness  in  holding, 
63 

Gymnasium,  72 

Habit,  curve  of,  31 
Hallucinations,    experiments 

upon,  218,  235 
Hamilton,  248 
Hearing,  101;  with  two  ears, 

116 
Heart,  185 
Helmholtz,  253 
Herbart,  242,  248 
Highest    audible    tone,    103; 

dependent  on  intensity,  106 
Holmgren  test,  137 
Hot,  reaction  to,  35;  hot  and 

cold,  87;  hot  spots,  88 
Hues,  121 
Hundredths     of     a     second, 

sign  for,  15 

Ideas,  235 

Illusion,  Aristotle's,  85;  of 
skin  space,  85;  of  visual 
space,  151;  distorted 
squares,  153;  enlarged 
angle,  153;  filled  space,  154; 
inclined  lines,  154;  parallel 
lines,  155;  straight  lines, 
156;  of  cornice,  156;  of 
rings,  156;  mistake  of  at- 
tention, 157;  of  coins,  158; 
of  depth,  159;  of  distance, 
159;  of  sky,  160;  of  moon, 
160;  of  Yale  clock,  162; 
experiments  upon,  218 

Imagination,  235 

Inaccuracy,  see  the  various 
experiments 

Inclined  lines,  159  ; 


Index,     of     inaccuracy,      55 

of  irregularity,  55 
Intensity  of  tones,  101 
Intermittent  activity,   32 
Interrupted    space,    illusions 

of,  85,  153 
Introspective    material,    232 
Introspective  method,  232 
Isolated  room,  28 

Jan  de  Meurs,  116 

Joy,  191 

Judgments,  logical,  42 

Key,  electric,  15,  28;  reac- 
tion, 29;  double,  29;  pistol, 
33;  runner's,  34;  touch,  35; 
five-knobbed,  40;  voice,  41  ; 
foot,  53;  orchestra  leader's, 

Knowledge,  the  fundamental 
method  of  acquiring,  1 ; 
threshold  of,  94 

Language,  rapidity  in,  50 
Latin,  rapidity  in  translating, 

50 
Latin  type,  38 
Law,   its  meaning,   238 
Laws,  of  change,  90,  111;  of 

attention,  196;  of  memory, 

205;  of  association,  237 
Learning  by  rote,  213 
Least  noticeable  change,  79, 

90,  111 
Least    noticeable    difference, 

81,  107,  139,  170 
Least   noticeable   sensations, 

see  Threshold 
Least  perceptible,   see  Least 

noticeable 
Lessons  in  observing,  8 
Letters,  recognition  of,  38 
Light,  reaction-time  to,  35 
Like  and  dislike,  177 
Location  of  sounds,  118 
Logical  judgments,  42 
Lowest  audible  tone,  102 
Lubbock,  7 
Lustre,    binocular,    175 


Index 


259 


Magician's   training,    see 
Robert-Houdin 

Magnesium  oxide,   159 

Map  of  hot  and  cold  spots,  88 

Mariotte,  148 

Marker,  see  Time-marker 

Marking  time,  63 

Material  of  psychological  in- 
vestigation. 231 

Materialism,  240 

Mathematics  in  psychology, 
250 

Mediate  association,  215 

Memory,  203,  235 

Mental  time,  see  Reaction- 
time,  Thinking-time 

Mental  work,  effect  on  ac- 
tion, 23 

Metaphysical  mania,  202 

Middle  tone,  113 

Mirror  fork,  67 

Mixing  yellow  and  blue,  128 

Alixture  of  colours,  123 

Mnemonics,  213 

Monochromat,     135 

Monocular  space,  151 

Monocular   vision,    145 

Moods,  191 

Moon  illusion,  160 

Mouth-key,  see  Voice-key 

Movement,  rhythmic,  52; 
steadiness  of,  61 ;  memory 
for,  203 ;  suggestion  of,  223 

Multiplication,  time  of,  42 

Muscle  sense,  71 

Music,  inspiriting  effect  of, 
73;  notation  for,  116 

Musk,  76 

Mystics,  238 

Names    for    odours,   92;    for 

tastes,  96 
Neutral  colours,  120 
New    Haven  school-children, 

see  Children 
New  psychology,  247 
Noise,  iOl 
Notation  for  pitch,   116;  for 

duration,  116;  for  intensity 

116 


Objective,  233 

Obliteration  of  intermediate 
associations,  215 

Observation,  1,  230 

Observing,  lessons  in,  8 

Odours,  effects  of,  in  grip,  76; 
names  of,  92 ;  groups  of,  93 ; 
experiments  in,  93 ;  alterna- 
tion of  95 

Olfactometer,  93 

Orchestra  leader,  57 

Organ  of  mind,  234 

Paints,  see  Pigments 
Parallel  lines,  illusion,    155 
Passage  of  a  star,  27,  226 
Perceptions,  234 
Perimetry,  146 
Personal  equation,   27,   225 
Piano  player,  58 
Pigments,  mixture  of,  126 
Pistol-key,  33 
Pitch,  lO'l 
Plato,  240 
Pleasure,  191 
Plethysmograph,  186 
Pneumatic  shoe,  52 
Pneumograph,  186 
Point  of  regard,  145 
Power  and  will,  69 
Practice,    22;   curve   of,    31; 

increases     steadiness,     64 ; 

influence  on  power,  72 
Prejudice,  2 
Pressure,  see  Touch 
Principle  of  forced  attention, 

214 
Properties  of  tones,  101 
Psychic  blind-spot,  151 
Pugilist,  45 
Pulse,  190 
Pun,  212 

Pure  white  pigment,  124 
Purest  colours,  120 

Quakers,  140 

Qualitative  experiments,  11 
Quantitative  experiments,  1 1 
Quick  observation,  9 


26o 


Index 


Racing  and  reaction-time, 
33 

Railways  and  colour-blind- 
ness, 136 

Rapidity  of  tapping,  IG;  of 
thought  and  action,  44;  in 
telegraphing  and  typewrit- 
ing, 51 

Reaction-key,  29 

Reaction-time,  25;  in  disease, 
33;  runner's,  34;  to  touch, 
35;  to  temperature,  35; 
to  light,  35;  decreases  with 
age,  36 

Recognition-time,  37 

Recognition  of  letters,   38 

Recording-drum,  see  Drum 

Recuperation,  32 

Red-blindness,  132 

Regard,  point  of,  145 

Relaxation,  32,  189 

Reserve  of  energy,  23 

Rhythmic  action,  52 

Ring  illusion,  156 

Robert-Houdin,  9,  217 

Romanes,  5 

Room,  isolated,  28;  reaction-, 
28 

Roughness,  86 

Runner's  reaction-time,  34; 
suggestion,  224 

Running,  52 

Safe  colour-vision,  139 

School  children,  see  Chil- 
dren 

Scientific  habits  of  thought, 
238 

Seeing  with  one  eye,  145 

Seeing  with  two  eyes,  163 

Sensation,  threshold  of,  94; 
weak  aids  stronger,  98 

Sensations,  234 

Series  of  taps,  16 

Shades,  122 

Shadows,  illusion,  161 

Shoe,  52,  53 

Sigma,  15 

Signals,  red  and  green,  136 

Simultaeous  acts,   20 


Singing,  accuracy  of,  67;  of 

intervals,  68 
Size,  and  distance,  159;  and 

suggestion,  219 
Skin,  see  Touch 
Sky  illusion,    160;  shape  of, 

160 
Slant  writing,  24 
Sleep,  238 
Smell,   92;  threshold  of    93; 

see  also  Odours 
Smells,  effects  of,  76 
Smoked  drum,  see  Drum 
Smoothness,  86 
Snapper-sounder,  119 
Sorrow,  191 
Sound,  reaction  to,  28 
Sounds,   101;  effect  on  grip, 

75 
Space,   touch,    83;   auditory, 

118;  visual,  145 
Spark-coil,  15,  20,  23,  43,  45, 

47,  54 
Spectrum,  124 
Sphygmograph,  186 
Spiritualism,  240 
Sportsman,  45 
Spot,  bhnd-,  148 
Spots,  hot  and  cold,  88 
Squeeze,  see  Power 
Stairway  illusion,  156 
Standard  white,  124 
Steadiness,  61 ;  gauge  for,  64; 

in  singing,  67 
Stereoscope,  165 
Stimulation,  189 
Straight  line  illusion,  156 
Strength  and  will,  72 
Strife,  of  nostrils,  95;  binocu- 
lar, 174 
Suggestion,  217 
Suggestion  blocks,  219 
Symmetry,  182 
System    of   colours,    122;   of 

greys,  120 

Tap  counter,  21 
Tapping,  15 
Taste  without  smell,  96 
Tastes,  76,  96 


Index 


261 


Telegraphing,  21 

Telegraph  key,  see  Key,  elec- 
tric 

Telescope,  27,  225 

Temperature,  reaction-time 
for,  35 ;  spots,  88 ;  and  pres- 
sure, 91 ;  influence  on  taste, 
100 

Temporary  blind-spot,  151 

Tension,  189 

Terror,  191 

Tests,  11 

Thinking  time,  37 

Threshold,  of  touch,  77;  of 
space,  83;  of  smell,  93;  of 
knowledge,  94 ;  of  sensation 
94;  of  recognition,  94;  of 
taste,  97;  of  difference  in 
pitch,  109;  of  change  in 
pitch.  111;  of  intensty  for 
hearing,  115 

Tickling,  78 

Time  and  action,  13 

Time-line,  14 

Time-marker,  14 

Time-memory,  215 

Time  of  day,  influence  on 
tapping,  17 

Time  of  perception,  30 

Time  of  reaction,  see  Reac- 
tion-time 

Time  of  thought,  see  Think- 
ing-time 

Time  of  volition,  30 

Tints,  122 

Tone,  reaction  to,  28; 
accuracy  in  singing,  67; 
properties  of,  101;  low- 
est audible,  103;  high- 
est audible,  104;  dis- 
crimination for,  107; 
notation  for,  116;  memory 
for,  208 

Tone-tester,  110 

Top,  for  colours,  123 

Touch,  reaction-time  for,  35; 
experiments    on,    77;    and 


temperature,  91 ;  and  taste, 

99 
Touch-key,  35 
Touch-weights,  77 
Translation,  time  of,  42 
Trichomats,  131 
Tuning-fork,  see  Fork 
Twenty  questions,  4 
Types  of  persons,  32 
Typewriti-ng,  51 

Uncertainty,  average,   205 
Unconscious  additions,  4 
Uncrossed  disparity,    169 
Untrustworthiness      of      the 
senses,  7 

Vertical  writing,  24 

Violet,  121 

Vision,  defective  colour,  138; 
monocular,  145;  distinct 
and  indistinct,  145;  field 
of,  145;  binocular,  163 

Voice-key,  41 

Volition,  234; 

Walking,  52 

Watching,  1 

Warm  colours,  132 

Warming  up,  22 

Warmth,     hallucination     of, 

218 
Weber,  252 
Weber's  law,  83 
White,  125 
Will,  64,  71 
Will-impulses,  21 
Wool-test,  137 
Work,  mental,  23 
Worsted  test,  137 
Writing,  24 
Writing-board,  23 
Wundt,  5,  105,  253 

Yellow  and  blue  pigments, 
128 


Ji  Selection  from  the 
Catalogue  of 

G.  P.  PUTNAMS   SONS 


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on  application 


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8.— Comparative  Physiology  of  the  Brain  and  Comparative  Psy- 
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LoEB,  M.D.,  Professor  of  Physiology  in  the  University  of  Chicago. 
Illustrated.     8°.     $1.75. 

"  No  student  of  this  most  interesting  phase  of  the  problems  of  life  can  afford  to  remain 
in  ignorance  of  the  wide  range  of  facts  and  the  suggestive  series  of  interpretations  which 
Professor  Loeb  has  brought  together  in  this  volume."— Joseph  jASTROV*r,  in  the  Chicago 
Dial. 

9. — The  Stars.  By  Professor  Simon  Newcomb,  U.S.N.,  Nautical  Al- 
manac Office,  and  Johns  Hopkins  University,  8°,  Illustrated.  Net. 
$2.00.     (By  mail,  $2.00.) 

"The  work  is  a  thoroughly  scientific  treatise  on  stars.  The  name  of  the  author  is 
sufficient  guarantee  of  scholarly  and  accurate  work." — Scientific  American. 

10. — The  Basis  of  Social  Relations.  A  Study  in  Ethnic  Psychology.  By 
Daniel  G.  Brinton,  A.M.,  M.D.,  LL.D.,  Sc.D.,  Late  Professor  of 
American  Archaeology  and  Linguistics  in  the  University  of  Pennsyl- 
vania ;  Author  of  "History  of  Primitive  Religions,"  "Races  and 
Peoples,"  "  The  American  Race,"  etc.  Edited  by  Livingston  Far- 
rand,  Columbia  University.     8°.     Net,  $1.50    (By  mail,  $1.60.) 

"  Professor  Brinton  his  shown  in  this  volume  an  intimate  and  appreciative  knowledge 
of  all  the  important  anthropological  theories.  No  one  seems  to  have  been  better  acquainted 
with  the  very  great  body  of  facts  represented  by  these  sciences." — Am.  Journal  0/ 
Sociology. 

II. — Experiments  on  Animals.  By  Stephen  Paget.  With  an  Intro- 
duction by  Lord  Lister.   Illustrated.    8".    Net,  $2.00.    (By  mail,  $2.20.) 

"To  a  large  class  of  readers  this  presentation  will  be  attractive,  since  it  gives  to  them 
in  a  nut-shell  the  meat  of  a  hundred  scientific  dissertations  in  current  periodical  literature. 
The  volume  has  the  authoritative  sanction  of  Lord  Lister." — Boston  Transcript. 

12. — Infection  and  Immunity.     With  Special  Reference  to  the  Prevention 

of  Infectious  Diseases.     By  George  M.  Sternberg,  M.D.,  LL.D., 

Surgeon-General  U.  S.  Army  (Retired).    Illustrated.    8°.    Net,  $1.75. 

(By  mail,  $1.90.) 

"  A  distinct  public  service  by  an  eminent  authority.  This  admirable  little  work  should 
be  a  part  of  the  prescribed  reading  of  the  head  of  every  institution  in  which  children  or 
youths  are  gathered.     Conspicuously  useful." — N.  V.  Times. 

13. — Fatigue.     By  A.  Mosso,  Professor  of  Physiology  in  the  University 

of  Turin,     Translated  by  Margaret  Drummond,  M.A.,  and  W.  B. 

Drummond,  M.B.,C.M.,  F.R.C.P.E.,  extra  Physician,  Royal  Hospital 

for  Sick  Children,  Edinburgh;    Author  of  "The  Child,   His  Nature 

and  Nurture."     Illustrated.     8°.     Net,  $1.50. 

"  A  book  for  the  student  and  for  the  instructor,  full  of  interest,  also  for  the  jntellieent 
general  reader.  The  subject  constitutes  one  of  tne  most  fascinating  chapters  in  the  oiS" 
tory  of  medical  science  and  of  philosophical  research." — Yorkshire  Post. 


1 4. — Earthquakes.    In  the  Light  of  the  New  Seismology.    By  Clarence 

E.   Button,   Major  U-   S.   A.      Illustrated.     8°.     Net,  $2.00.     (By 

mail,  62.20.) 

'The  book  summarizes  the  results  of  the  men  who  have  accomplished  the  great 
^hi..  -s  in  their  pursuit  of  seismological  knowledge.  It  is  abundantly  illustrated  and  it 
fills  a  place  unique  in  the  literature  of  modem  science," — Chicago  Tribune. 

15. — The  Nature  of  Man.  Studies  in  Optimistic  Philosophy.  By  Elie 
Metchnikoff,  Professor  at  the  Pasteur  Institute.  Translation  and 
introduction  by  P.  Chambers  Mitchell,  M.A.,  D.Sc.  Oxon.  Illus- 
trated.    8°.     Net,  $2.00. 

"  A  book  to  be  set  side  by  side  with  Huxley's  Essays,  whose  spirit  it  carries  a  step 
further  on  the  long  road  towards  its  goal." — Mail  and  Express. 


The  following  volumes  are  in  preparation  : 

Meteors  and  Comets.     By  Professor  C.   A.  Young,  Princeton  Uni 
versity. 

The  Measurement  of  the  Earth.  By  Professor  C.  T.  Mendenhall, 
Worcester  Polytechnic  Institute,  formerly  Superintendent  of  the  U.  S. 
Coast  and  Geodetic  Survey. 

The  History  of  Science.    C.  S.  Pierce. 

Recent  Theories  of  Evolution.      By  J.  Mark  Baldwin,  Princeton 

University. 

The  Reproduction  of  Living  Beings.  By  Professor  Marcus  Hartog, 
Queen's  College,  Cork. 

Man  and  the  Higher  Apes.     By  D..  V  Keith,  F.R.C.S. 

Heredity.     By  J.  Arthur  Thompson,  School  of  Medicine,  Edinburgh. 

Life  Areas  of  North  America :  A  Study  in  the  Distribution  of 
Animals  and  Plants.  By  Dr.  C.  Hart  Merriam,  Chief  of  the 
liological  Survey,  U.  S.  Department  of  Agriculture. 

Age,  Growth,  Sex,  and  Death.  By  Professor  Charles  S.  Minot, 
Harvard  Medical  School. 

History  of  Botany.     By  Professor  A.  H.  Green. 

Planetary  Motion.    By  G.  W,  Hill. 


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